User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Mon Jul 02, 2018 10:13 am

tlfong01 wrote:
Mon Jul 02, 2018 4:51 am
Now I can sleep well.
Actually I am not too sure if I can sleep well to night, because I might have a bad dream of KY019 relay testing.

I have completed all the wiring and can start testing any time. But I am getting nervous, perhaps because the terrible electrical shock experience a couple of years ago still stays in my sub conscious mind. I still remember that one of two years afterwards, from time to time I had bad dreams of seeing my hand touching a hot electrical wire, getting a surprising huge pain, and could not shake away the wire. And I was very frightened and sadly thought that was the end of my life, ... but of course I woke up and very relieved to find that it was just a dream, ...

In that one or two years I thought I might have developed some mild form of PTSD. But these two years I no longer have the same bad dreams, so I think time has cured me, ...

But a couple of minutes ago I heard from radio a very sad news of a young boy got a fatal lighting strike.

I got a bad feeling. So I am now going jogging to release stress, ...

Update the morning after - I did not sleep well, and woke up around 2am, though no bad dreams before waking up.

Student, 18, dies after being struck by lightning while hiking in Hong Kong - SCMP updated 2018jul03Tue
http://www.scmp.com/news/hong-kong/comm ... rm-warning

Ian Lo Go-yin had recently completed his final year at South Island School in Aberdeen, and was with a group of friends in Ma On Shan Country Park when the freak accident happened.
Attachments
HVa2Bkb[1].jpg
HVa2Bkb[1].jpg (142.5 KiB) Viewed 836 times
Last edited by tlfong01 on Tue Jul 03, 2018 5:58 am, edited 1 time in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Mon Jul 02, 2018 2:16 pm

Mortimer wrote:
Mon Jul 02, 2018 8:45 am
Looks good.
It is OK as a prototype. If test results is good, next step is to upgrade to version 2.0 with the following changes.
  • 1. Number of relay channels = 8
  • 2. Chassis size = twice as big.
  • 3. 12 terminal bar
  • 4. 6mm x 50mm earth stud.
  • 5. / to continue, ...
Attachments
Xpa4siL[1].jpg
Xpa4siL[1].jpg (73.75 KiB) Viewed 824 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Mon Jul 02, 2018 3:25 pm

tlfong01 wrote:
Mon Jul 02, 2018 10:13 am
I have completed all the wiring and can start testing any time.
Before any test, I will first do a NO POWER, open/short check, using a multimeter. This is to make sure the following.

1. All point to point soldering are shorted (almost zero resistance).

2. All neigbouring points are open (almost infinite resistance).

3. Mains L points are shorted to themselves, but open to N, E points. Similarly for N and E.

4. Transformer input and output are connected properly.

5. Manual switches are working OK.

6. /To continue, ...
Attachments
lIXFbAf[1].jpg
lIXFbAf[1].jpg (156.12 KiB) Viewed 807 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Tue Jul 03, 2018 5:48 am

tlfong01 wrote:
Mon Jul 02, 2018 3:25 pm
Before any test, I will first do a NO POWER, open/short check, using a multimeter.
While tidying up things I found a "Mains status plug" and a "Voltage detector pen" which should be lying in the tool box collecting dust for a couple of years. I never used them. I think they are glad that the time has finally come to serve their master and even save his life, ...
Attachments
bl5awAb[1].jpg
bl5awAb[1].jpg (77.81 KiB) Viewed 774 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Tue Jul 03, 2018 7:41 am

tlfong01 wrote:
Mon Jul 02, 2018 3:25 pm
Before any test, I will first do a NO POWER, open/short check, using a multimeter.
I used my cheap multimeter to measure the resistance between two points. The readings are not very stable, and take a couple of seconds to settle down. (I guess the industrial standard multimeter should give fast and stable readings).

Anyway, the results looks OK, as summarized below.

Expected shorts = < 1.5 Ohms

Expected opens = > 200 Mega Ohms
Attachments
71QXCkk[1].jpg
71QXCkk[1].jpg (90.15 KiB) Viewed 757 times
Last edited by tlfong01 on Tue Jul 03, 2018 8:59 am, edited 1 time in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Tue Jul 03, 2018 8:33 am

tlfong01 wrote:
Tue Jul 03, 2018 7:41 am
I used my cheap multimeter to measure the resistance between two points.
Anyway, the results look OK, as summarized below.
Expected shorts = < 1.5 Ohms
Expected opens = > 200 Mega Ohms
Next step is to play with the voltage detector pen and the mains LNE fault detector plug.

I used to have a neon lamp screwdriver which I found very good. To detect a live wire, I use the neon screw driver to touch the hot line wire (I forgot if I should use my bare foot to touch the floor) , the neon lamp grows if the wire is hot.

So some years back when the electronic DIY shop gave me this detector pen for free, as my birthday gift, I did not appreciate it at all, because I found that thing a bit bulky, and also need to use a battery (AAA?, I forgot), what if the battery runs out and I could not find a new battery? So I thought I would still use my old friend, the neon screwdriver, and give away my birthday gift to a friend who likes to play with new toys. But I have not seen my friend for a long time, so I still keep my gift. Thus this unwelcome birthday gift has been sleeping in my tool box for years, collecting dust.

Just now I played with it and very surprisingly found it very nice, for the following reasons:
  • 1. It is smart remote sensing. I don't need to touch the wire. I just place the plastic tip of the detector near to the socket, about 1 cm from L, N, or E.
  • 2. What surprised me is that the thing is so sensitive that if I move near N, green light is on. When I move to L, red light is on, the thing also makes a warning beep. One thing I don't understand is that even if I move the top to E, red light and beep also on. I thought E should do nothing.
  • 3. I googled and skimmed through the user manual and found it it can also detect low AC power. So I can use it for my 12V/24VAC power, but I have not tried it yet.
The line fault detector plug is also good. I plugged it to a power socket, but nothing happened. When I switched on power, all three lamps lighted up, meaning everything OK!

I should later check with my relay box, to see if I remove E, remove L, swap N and L, etc, this smart plug can warn me and tell me what goes wrong.

So I almost missed a good new tool because I thought old tools are better than new. This reminds me the following user who keeps on learning new things,

Why are Newbie's ignored? - BoyOh, Thu Apr 12, 2018
viewtopic.php?f=91&t=210678&p=1300622#p1300914

... The trouble is they won't [want] to learn electronics in in a short week end course,

I'm 86yrs and still learning
, One advantage I had is i served a 7yre electrical apprenticeship way back in 1945.


No computers No calculators No transistors and NO GOOGLE.

When TTL was developed I had to start from scratch, but understood Ohms Law. But now electronics is all plug and play. Not much incentive to build circuits. ...


Regards BoyOh Retired Electrical / Electronics Technician
( Selby, North Yorkshire.UK)
Attachments
qepCCkj[1].jpg
qepCCkj[1].jpg (75.47 KiB) Viewed 745 times
Last edited by tlfong01 on Tue Jul 03, 2018 1:11 pm, edited 2 times in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
Mortimer
Posts: 891
Joined: Sun Jun 10, 2012 3:57 pm

Re: Relay Module KY-019 5V

Tue Jul 03, 2018 9:27 am

tlfong01 wrote:I'm 86yrs and still learning,
:shock: Wow! Good going. Gives us all hope! :lol:
My grandmother learned to use a computer for word processing, printing, emails and a little web browsing at the ripe age of 88, and was using a computer up until the age of 94 when her eyesight let her down.
tlfong01 wrote: No computers No calculators No transistors and NO GOOGLE.
I go back past NO GOOGLE, we had things call libraries full of reference books.

Past "No computers" in the sense that no-one had one at home, they were a very expensive novelty. They started appearing in schools during my secondary school education, when they got one Link 380Z for the whole school. Up to then we used a teletype terminal over acoustic modem to the local college mainframe. As there was only one terminal, whilst waiting your turn, you wrote your Basic programs on paper, and then hand punched them onto paper tape!

My first calculator was a mechanical device! My first electronic one was a kit. Calculators were otherwise expensive toys. I can remember my Dad spending an absolute fortune on a Sinclair Cambridge Memory pocket calculator, which I still have today!!

Transistors however were before my time, although I do have a 1950's Pye Fenman II valve radio, that used to belong to my Grandfather, which still works as well!

User avatar
davidcoton
Posts: 3156
Joined: Mon Sep 01, 2014 2:37 pm
Location: Cambridge, UK

Re: Relay Module KY-019 5V

Tue Jul 03, 2018 9:35 am

Just some notes on your mains detection tools:
  1. Neon screwdrivers are not regarded as safe and should not be used.
  2. Mains status plug is a quick and easy confirmation that wiring is correct to that point. Should not be used to prove a circuit is off (safe to handle).
  3. No contact "volt stick" are useful but can give false readings. Should not be used to prove a circuit is off (safe to handle).
  4. Cheap multimeters will give useful comparative readings, but are not calibrated and are not testing to the same standards as electricians' meters. Low resistance needs a meter capable of supplying 10A, insulation tests require a test voltage double the normal supply voltage.
"Thanks for saving my life." See https://www.raspberrypi.org/forums/viewtopic.php?p=1327656#p1327656
“Raspberry Pi is a trademark of the Raspberry Pi Foundation”

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Wed Jul 04, 2018 7:13 am

tlfong01 wrote:
Tue Jul 03, 2018 7:41 am
I used my cheap multimeter to measure the resistance between two points. ...
Anyway, the results looks OK. ...
Before the power on test, I though I should do a quick open short check one more time. This time I found an unexpected open fault. It took me almost one hour to locate the cause of trouble - a intermittently poor contact fuse holder.

The troubleshooting took me so long because I have only a schematic, but no layout and wiring diagram, and all the exposed contact points are now insulated by heat shrunk plastic tubes.

Anyway, I replaced the HK$3 faulty fuse holder (the cheapest I could find).
Attachments
A6RYQz2[1].jpg
A6RYQz2[1].jpg (99.21 KiB) Viewed 700 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
Mortimer
Posts: 891
Joined: Sun Jun 10, 2012 3:57 pm

Re: Relay Module KY-019 5V

Wed Jul 04, 2018 8:22 am

The checking was worthwhile then?
Good job! :D

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Wed Jul 04, 2018 9:25 am

tlfong01 wrote:
Wed Jul 04, 2018 7:13 am
Anyway, I replaced the HK$3 faulty fuse holder (the cheapest I could find).
I connected AC220V power and tested again. But output socket still had no power. This time I was smart and immediately guessed correctly that other cheap fuse holder was also bad. After replacement, everything went well, including my good old neon screwdriver, with my bare foot assisted line checking.
Attachments
w8BiIVI[1].jpg
w8BiIVI[1].jpg (118.49 KiB) Viewed 678 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Thu Jul 05, 2018 7:32 am

davidcoton wrote:
Tue Jul 03, 2018 9:35 am
Just some notes on your mains detection tools:
  1. Neon screwdrivers are not regarded as safe and should not be used.
  2. Mains status plug is a quick and easy confirmation that wiring is correct to that point. Should not be used to prove a circuit is off (safe to handle).
  3. No contact "volt stick" are useful but can give false readings. Should not be used to prove a circuit is off (safe to handle).
  4. Cheap multimeters will give useful comparative readings, but are not calibrated and are not testing to the same standards as electricians' meters. Low resistance needs a meter capable of supplying 10A, insulation tests require a test voltage double the normal supply voltage.
  • 1. Neon screwdrivers are not regarded as safe and should not be used.
I always thought that my neon screwdriver was as safe as the body temperature thermometer. So I wikied and now I know why it is not.
  • 2. Mains status plug should not be used to prove a circuit is off.
I see. So if it says not safe then it is not safe. But if it says safe, it might might not be safe. In other words, might be false negative.
  • 3. "volt stick" can give false readings)...
Same as 2. above.
  • 3. Cheap multimeters will give useful comparative readings, ... Low resistance needs a meter capable of supplying 10A, insulation tests require a test voltage double the normal supply voltage.
I agree. However, cheap multimeters are good enough for hobbyist's Micky mouse projects. That is what the professional engineers call "appropriate technology". And so the accurate methods of measuring low resistance and high insulation is not that appropriate for me.
By the way, I watched a RCBO youtube video and found the engineer using a neon screw driver like voltage detector. Is his a safe tool?
https://www.youtube.com/watch?v=CsHMIcmXiO0
Attachments
jXsKnn2[1].jpg
jXsKnn2[1].jpg (20.56 KiB) Viewed 640 times
Last edited by tlfong01 on Thu Jul 05, 2018 1:06 pm, edited 3 times in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Thu Jul 05, 2018 7:42 am

Mortimer wrote:
Wed Jul 04, 2018 8:22 am
The checking was worthwhile then?
Good job! :D
Thank you. TDD or Testing Driven Development is the software method I have been following for some time.

However, I found it not always that good for hardware projects.

Test-driven development - Wikipedia
https://en.wikipedia.org/wiki/Test-driven_development

Continuous testing - Wikipedia
https://en.wikipedia.org/wiki/Continuous_testing
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Thu Jul 05, 2018 9:17 am

tlfong01 wrote:
Wed Jul 04, 2018 9:25 am
I connected AC220V power and tested again. But output socket still had no power. This time I was smart and immediately guessed correctly that other cheap fuse holder was also bad.
After replacing the two bad fuse holders, I resumed testing again. But very annoyingly, I found the newly replaced fuse holder no longer worked. So it is another intermittently bad fuse holder. Anyway, I hit the box a couple of times, and the sleeping fuse holder woke up working again.

I then tested a 220V 5W lamp (I forgot if it is LED) and everything worked OK. Next step is to test a AC220V motor.
Attachments
cMH0OV3[1].jpg
cMH0OV3[1].jpg (53.97 KiB) Viewed 618 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
Mortimer
Posts: 891
Joined: Sun Jun 10, 2012 3:57 pm

Re: Relay Module KY-019 5V

Thu Jul 05, 2018 9:31 am

Ah! But those checks are not "testing" the project in the same sense that TDD uses testing. In TDD the tests are to see that the desired functionality of the project is being achieved. The checks you made were simply checks that the thing was safe to even turn on.

I would also say that this is not a Mickey Mouse project, and any time you're developing something uses mains Voltages and currents, trivialising the project is not necessarily a good thing. Mains power should always be respected. I do agree that you often have to make do with what you've got, but to give you a view of what we have to do with these sorts of projects in industry...

The checking of safety earths cannot properly be tested using a multi-meter, because they cannot drive enough current. We are required to test safety earths at a minimum of 25A, which requires quite expensive kit. We use a Clare A433R, which can push up to 30A through the safety earth wiring. The theory being the safety earth will not be able to work unless it can sink the whole supply current to ground for long enough to blow the supply fuses or trip breakers. A multi-meter won't tell you that. In your case however, it is a relatively simple setup, and a careful inspection along with basic continuity checks should be sufficient.

For insulation checks we are required to test at 500Vdc, again something your multi-meter cannot do. Your multi-meter will tell you that you have isolation at a couple of Volts. However when the mains is switched on, for a 240Vac supply you will have over 300V peaks on your wiring. Air breaks down at 3000V/mm or in other words, if you have any gaps between wires of 0.1mm these would show as open circuit to your multi-meter, but possibly short circuit at mains Voltage if it flashes over the gap. Again a good inspection couple which Ohms checks should suffice.

In either case precautions when turning on for the first time, e.g:
  • Switch on remotely if possible for the first time. I.e. turn any switches to on position on the project, then stand back and plug into a switched socket and turn on.
  • Once turned on, if you intend measuring for Voltages use one hand only, the other kept well away and behind your back.
  • Let someone know what you're doing, and what to do if it goes wrong, i.e. where to isolate power to make things safe, and to not touch you before doing that.

Paul Hutch
Posts: 282
Joined: Fri Aug 25, 2017 2:58 pm
Location: Blackstone River Valley, MA, USA

Re: Relay Module KY-019 5V

Thu Jul 05, 2018 4:04 pm

tlfong01 wrote:
Wed Jul 04, 2018 7:13 am
Anyway, I replaced the HK$3 faulty fuse holder (the cheapest I could find).
My general rule of thumb is to never buy the cheapest I can find of any safety device. I only buy safety devices made by manufacturers that I know and trust.

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 2:28 am

Paul Hutch wrote:
Thu Jul 05, 2018 4:04 pm
My general rule of thumb is to never buy the cheapest I can find of any safety device. I only buy safety devices made by manufacturers that I know and trust.

Well, #MeToo, but, ...

Update 2018jul06hkt2153
My use of the word "cheapest" is rather misleading. My apologies. For life critical devices, I do get the most reliable consumer grade products. For example, For 13A plugs I do buy the most reliable and most expensive ones I can find in commercial stores. But I do know that public utilities such as hospitals, use plugs perhaps three times as expensive, and of course more reliable, as consumer grade.
Attachments
cCuwZcg[1].jpg
cCuwZcg[1].jpg (66.92 KiB) Viewed 491 times
Last edited by tlfong01 on Fri Jul 06, 2018 2:03 pm, edited 1 time in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
Mortimer
Posts: 891
Joined: Sun Jun 10, 2012 3:57 pm

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 5:46 am

As a general rule, yes, but a fuse-holder is hardly a complicated thing and even a cheap one should serve its purpose.

Just had a thought... Have you got the correct sized fuse in the holder? Is it possible the fuses you have are too short for the holder and not pressing the contacts properly?

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 6:37 am

Mortimer wrote:
Fri Jul 06, 2018 5:46 am
As a general rule, yes, but a fuse-holder is hardly a complicated thing and even a cheap one should serve its purpose.

Just had a thought... Have you got the correct sized fuse in the holder? Is it possible the fuses you have are too short for the holder and not pressing the contacts properly?
  • 1. Have you got the correct sized fuse in the holder?
Oh my goodness! I never thought about that. But then I remember one thing.

All these years I always use a short one fuse holder and never had any problem. This time I am doing a mighty 200VAC mains project, so I thought I should use a respectably mighty fuse holder to show off my advanced knowledge and skills, and to build up my reputation.

I still remember when I bought the fuse holder from the DIY shop, I did ask the shop keeper if I had selected the right size of fuse for the big fuse holder. She went to the shelves to check out and after some fitting, told me that I should also buy the big fuses. The big fuses are marked something like BSxxxx. I also asked her if there are only two sizes, if not big then small. She said so, ... So I bought big holders, and a couple of "compatible" big fuses.

Just now I used my ruler (I forgot if I should use the word "ruler", which is for pupils, not for professionals) to check out. The results is the following picture.
Attachments
a3aSZ4h[1].jpg
a3aSZ4h[1].jpg (159.43 KiB) Viewed 538 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 8:34 am

tlfong01 wrote:
Thu Jul 05, 2018 9:17 am
Next step is to test a AC220V motor.
Since all the wiring tested good, I no longer need the 3 manual switches to simulate the relays. From now on, I will use the real thing, the quad KY019 relay module.

I first checked the NC (Normal Close) circuit of three relays for 220VAC, 12VAC, and 24VAC. The line status plug shows everything OK.

There is one relay left over, so I will use it for controlling a 5VDC 12VDC supply. Next step is to see if 5V signals can control the 4 relays. The following is a summary of the relay assignment.

Quad KY019 Relay Module Assignment

Relay 1 = 220VAC
Relay 2 = 12VAC
Relay 3 = 24VAC
Realy 4 = 5VDC 12VDC

update 2018jul07hkt1550
I changed my mind. Relay 4 will control a 12V supply, not 5V.
Attachments
k45VbfT[1].jpg
relay box
k45VbfT[1].jpg (54.34 KiB) Viewed 521 times
Last edited by tlfong01 on Sat Jul 07, 2018 7:52 am, edited 1 time in total.
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
Mortimer
Posts: 891
Joined: Sun Jun 10, 2012 3:57 pm

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 11:22 am

So you had BS1362 fuses in a 6x30mm holder? If so no wonder it was unreliable. BS1362 panel fuse holders exist I believe.

When you start using electric motors, you might want to consider changing any glass fuses in circuit to ceramic ones, like the BS1362. Genuine BS1362 fuses have quartz sand in them them quenches any arc when the fuse blows and ensures the circuit it broken. Glass unfilled fuses could arc when then blow and continue passing current. You can get the same sort of fuse in 5x20mm size too (e.g. https://uk.rs-online.com/web/p/cartridge-fuses/0563340/). Again they will be ceramic, so you can't see into them, and filled with quartz sand.

Paul Hutch
Posts: 282
Joined: Fri Aug 25, 2017 2:58 pm
Location: Blackstone River Valley, MA, USA

Re: Relay Module KY-019 5V

Fri Jul 06, 2018 7:53 pm

Mortimer wrote:
Fri Jul 06, 2018 5:46 am
As a general rule, yes, but a fuse-holder is hardly a complicated thing and even a cheap one should serve its purpose.
I've seen cheap brands with low quality housing materials crack and break leaving the wires shorting to the enclosure. I generally buy Bussmann or LittleFuse brand holders, they are higher priced but with mains voltage I feel it's well worth it. Now if you are only using them for speaker fuses or other low voltage applications then the cheap ones are fine from a safety perspective.

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Sat Jul 07, 2018 8:00 am

tlfong01 wrote:
Fri Jul 06, 2018 8:34 am
tlfong01 wrote:
Thu Jul 05, 2018 9:17 am
Next step is to see if 5V signals can control the 4 relays.
Quad KY019 Relay Module Assignment
Relay 1 = 220VAC
Relay 2 = 12VAC
Relay 3 = 24VAC
Realy 4 = 12VDC
Now I am testing the relay box off power, with following setup.
1. 220AV power off
2. 12VDC power off
3. 5V power on
4. IN1, 2, 3, 4 manual connect to 5V power.
4. Ears to listen to relay on/off clicks
5. Multimeter to check if relay COM/NO open/short

Everything went well. Next step is to test the relay box with 220VAC power on.
Attachments
dfzXJnE[1].jpg
dfzXJnE[1].jpg (95.52 KiB) Viewed 454 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Sat Jul 07, 2018 2:43 pm

davidcoton wrote:
Tue Jun 12, 2018 3:48 pm
And what happens if someone takes you project and connects it to a circuit where there is no ... RCD, or where it has failed?
Safety with mains electricity is all about multiple layers of safety.
Portable RCBO
Now I have another thought. Perhaps I can bring my own portable RCBO which plugs into a standard mains socket. In other words, now there are two layers of safety, main RCBO, portable RCBO.
Attachments
TVLOPSw[1].jpg
TVLOPSw[1].jpg (147.8 KiB) Viewed 429 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

User avatar
tlfong01
Posts: 551
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: Relay Module KY-019 5V

Sat Jul 07, 2018 3:13 pm

tlfong01 wrote:
Sat Jul 07, 2018 2:43 pm
Portable RCBO
Now I have another thought. Perhaps I can bring my own portable RCBO which plugs into a standard mains socket. In other words, now there are two layers of safety, main RCBO, portable RCBO.
I googled and found many RCBOs I can choose. I finally chose Schneider Easy9 2P.
Attachments
Zuw51rN[1].jpg
Zuw51rN[1].jpg (58.22 KiB) Viewed 425 times
I am an electronics hobbyist, started playing relays 3 months ago. I found things confusing. Luckily Google my friend makes me great again! :)

Return to “Automation, sensing and robotics”

Who is online

Users browsing this forum: markkuk and 14 guests