Do not confuse the relay coil voltage with the input control voltage. The relay coils are made with many different voltages. 3,5,6,12,24 etc. When they say 'x Volt relay' they are usually referring to the coil voltage not the input control voltage.Learning101 wrote: ↑Sat Feb 10, 2018 10:59 amHi, I'm trying to get a project together and I need to power a 24vac solenoid for short periods.
I understand the easiest off the shelf way is with a relay, (please correct me if I'm wrong)
Would this relay be suitable? https://www.amazon.co.uk/Elegoo-Channel ... B06XK6HCQC
It does say 5v and I know the GPIO is 3.3v but I don't seem to be able to find 3.3V relays! Would it still work?
Any advise greatly appreciated.
Thanks for you help, if it worked without the transistor and resistor, would there be anything else I need to put between the PI and the relay? Or not?pcmanbob wrote: ↑Sat Feb 10, 2018 11:19 pmThe relay board you have chosen may work, some of these 5V relay boards do work with the pi gpio and some don't, it seems to be pot luck as to whether they work or not.
You can always make them work and be active high with a simple transistor & resistor interface for each relay input.
Hi, so the solenoids are salvaged off a Coinco Global 2 coin mech, MDB version.pcmanbob wrote: ↑Tue Feb 13, 2018 11:29 pmIf you know what voltage they operate at then it's a simple thing to if they work on DC as you can use a simple multimeter set to amps to measure the current drawn, but your original post said 24v AC to measure AC amps you will need a clipon ammeter.
You could get estimated current if you know the operating voltage and you can measure the coil resistance using voltage / resistance = Current.
Can you give use any information on the solenoid valve you are using
Make, model, supplier ?
Hi Thanks, what is the best way to supply 6v, would it be with an adapter like this,pcmanbob wrote: ↑Fri Feb 16, 2018 7:38 pmThe problem you face with the solenoids having no markings is that even if the coin mech is powered from 34v DC there is nothing to say the solenoids will also be powered from the same 34v DC the coin mech may have output a different voltage to drive them.
So what you could do is using a digital multi meter set on ohms measure the resistance of the coil., then using different voltages
use the formula voltage / resistance = Current to work out the current that will flow for a given voltage.
if you say the wire is very thin then your probable want a current of maybe 100 -500 ma to flow ( thats 0.1 to 0.5 A )
this way you could get an estimate of the required voltage to operate the solenoid.
I would suggest you try voltages of 6,12,18,24,34V
once you have an idea of the voltage you can but test a solenoid and see if it works, but I would be ready to disconnect the power in the even you have it wrong and things start to smoke, it going to be a case of trail and error so be prepared for failure.
Have you done the calculations I suggested and decided that 6v is the correct voltage to use or are you just guessing ?
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