Raspberry Pi Forums

Is it possible to give signal directlly from raspberry to Electromagnetic lock, to open ?
http://www.electro-tech-online.com/cust ... ocks-1.jpg

Not directly. You will need to add external circuit(s) such as a relay board. Give a link to a data sheet or user manual for the lock.

A relay board wired to the release button terminals should work.

What relay board would be best ? and i didnt understod part about "release button terminals"

gigi5 wrote:What relay board would be best ? and i didnt understod part about "release button terminals"

How far away from the lock will the RPi be? You can use a 5V relay board powered from the RPi or a 12V 24V relay if powered by the lock power supply depending on which voltage you want to use for the lock.

Something like this: http://www.sainsmart.com/arduino-pro-mini.html

Look at the wiring diagram in your link and find the release button(s).

rpi will be very close, i mean almost in same position.

All you need are two transistors, some resistors, a diode and a relay.

solar3000 wrote:All you need are two transistors, some resistors, a diode and a relay.

You forgot one very important item. The circuit board. Not feasible for most novice users though a 'proto' board would work.
The off the shelf relay boards contain all the needed parts and are so cheap it's not worth making your own boards.