Wiring a relay board

Thread Starter

quique123

Joined May 15, 2015
405
How about a bluetooth development board like https://www.sparkfun.com/products/15025 and one of the many of relay boards online designed for a PI? Look for bluetooth development board online and you'll find a few more options. It would end up being a matter of connecting wires between the development board and the relay board.
OK but this is a Bluetooth board which I would have to connect to a set of two or three relays just the same isn’t it? What I was wondering is if there was some sort of relay with each bridge board which are usually commonly used to control in your actuators in such a way that you don’t use so many relays as somebody in the above thread suggested.

I'll try to measure the current today
 

Thread Starter

quique123

Joined May 15, 2015
405
OK I put the multimeter on the amperage setting and when I measured the current in the extending direction it measured between 0.2 and 0.4 A until it reached the end at which point it jumped to about 5.4 but then it immediately dropped back down to zero. Then I switched the direction of the cables and ran it again in the retraction mode and again it ran between .2 and .4 A until it reached the end which is when it dropped down to zero.
 

geekoftheweek

Joined Oct 6, 2013
1,201
OK but this is a Bluetooth board which I would have to connect to a set of two or three relays just the same isn’t it? What I was wondering is if there was some sort of relay with each bridge board which are usually commonly used to control in your actuators in such a way that you don’t use so many relays as somebody in the above thread suggested.
Ahh... I see where you are trying to go now. Personally at this point I would build my own board. A DPDT relay for the reverse and a simple transistor for low side switching. A couple diodes and resistors and some programming.

I don't have experience myself either building or using one, but there should be an H bridge board you could use. That would eliminate all relays.

Good luck!
 

LesJones

Joined Jan 8, 2017
4,174
Re post #42
It looks like the actuator does not use limit switches to detect end of travel but it does sense end of travel by sensing over current which shuts off the power to the actuator. (I use this method myself with curtains as there was no easy way to fit limit switches. It has been working for about 14 years now.) You do not need to do anything to stop the actuator. Just drive it forward and reverse. There are a few ways to do this.
1 - If you have a -24 volt supply as well as a plus 24 volt supply you can do it using one relay output.
2 - You can use two relay outputs from the relay board with a single supply.
3 - You can use a single relay output driving the coil of a DPDT relay.
4 - IF YOU CAN FIND A DPDT relay withe THE SAME COIL RATINGS as the relays on your board then you could remove one relay from the board and connect the coil of the DPDT relay to the connection points for the relay removed from the board.
5 - You could use an H bridge as has been suggested.
NOTE The fact that the actuator takes about 6 amps just before it shuts off it's power means that your power supply must be capable of supplying this current for a short time.

Les.
 
Last edited:

LesJones

Joined Jan 8, 2017
4,174
I can't be certain that the picture of you wiring is correct as I don't know what the other end of the wires connect to.. If these assumptions are correct it should work. Black and red are from the power supply. The two yellow wires connect to the motor.
Note There are two off states. One with both relays de-energised. the other with both relays energised.

Les.
 

Thread Starter

quique123

Joined May 15, 2015
405
Yes those assumptions are correct.

As for your note, so you mean that to extend the actuator I need to energize both relays and retract it I need to de-energize both relays?
 

LesJones

Joined Jan 8, 2017
4,174
NO. With both relays not activated BOTH motor wires will be connected to negative.(So there is no voltage across the motor.) With both relays activated both motor wires will be connected to positive so again there will be no voltage across the motor. Activating one relay will extend the actuator. Actuating only the other relay will retract the actuator. By changing the wiring it could be made to behave the way you describe in post #47. I did think of suggesting cutting the track between the driver transistor to one relay and the relay and then connecting that relay coil in parallel with another relay (So that the signal to one relay would activate two relays.) That would mean that when that channel was off it would drive the actuator in one direction. When it was on it would drive the actuator in the other direction. So in effect we would have created a DPDT relay from two SPDT relays. To do that you would have to check that the current rating of the driver transistors was high enough to drive the coils on two relays. You would still have lost a channel on the board as there would be no relay on the output of that channel.

Les.
 

Thread Starter

quique123

Joined May 15, 2015
405
Ok i finally got around to trying today and it works fine. Now I just need to migrate my old code in order to wire in my outside lights.

Thanks guys
 
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