Yes. A standard looking wall switch will work if its rated for 20 amps, but most of them are rated at 15 amps.
It really comes down to knowing how much current the motor really takes.

 

I've got all the other stuff you listed in addition to what I listed. I am not using any crimp fittings; I'll solder and shrink tube everything. I have relay sockets for the relays with 12 inch pigtails. I like things nice and tidy and the enclosure all this will be in will be no different. What's your thoughts on using the household toggle switch (post 59) for the overall power kill? I am not finding any switches that I like with mouser. Todd

 

Never mind, you beat me at posting. Your last post answered my last question and wasn't posted yet when I was typing. Thanks, Todd

 

I'd like to stop at this time to say that strantor did a world class job of cutting this to the minimum number of parts and arranging them so that each one suffers the least amount of stress in doing its job. Nobody could beat this design for efficiency or reliability, given the starting point we had.

 

I highly agree and greatly appreciate everyone that contributed to this project. I'll place the order tonight ( in a few minutes), it should take 3 or 4 days (probably Wed. or Thurs.) to get them. I'll start once they get here and ask for any help should I need it at that time. Then I'll give a progress report. Thanks!!!!! Todd

 

Well I just got back from a 3 day weekend away from my puter. I see you guys sorted everything out. Thanks #12. iflygiantrc, it would be nice to hear some feedback after you get this up and going.

 

You bet, bear with me for awhile, I'm not even slated to get the parts till Monday according to UPS. Once I do and get it together, you guys will be the first to know. Thanks again, Todd

 

This isn't the first chicken coop thread. It would make a fine addition to the "Finished Projects" section.

 

A little troubleshooting. I believe that I have everything hooked up as required. I don't have the 3 position (open/auto/close) switch and it won't be in for awhile but I do have everything else. I wired it for auto only and when I power it on, both relays immediately click so that instead of being in the NC = grounded, they activate and go to the NO = + position. With both limit switches closed, and the night watchman in daylight mode, the motor turns CW. when it hits the Open position and opens that limit switch the motor shuts off. When covering the eye and it goes into night mode, the motor activates and moves, once again in a CW direction, not in the needed CCW. If you open what is the closed limit switch (simulating that the motor reversed) then the motor stops as it should. Now, when you simulate daylight mode to start it all over, nothing happens. The problems as I see it are that (1) both relays are activating when the system is powered on, (2) the motor is not reversing when the system is supposed to call for it. Also, I don't know if it is significant but when the night watchman is powered on (not hooked up to this system) a yellow LED comes on when in the night mode and goes out when in daylight (not supplying power), it is on all the time when hooked up to the system so it is getting back-fed with power. What have I hooked up wrong? Also, I was just looking at the wiring diagram and the when in the closed position, there is no limit switch in the path. Wouldn't this mean that I have to quickly toggle it back to automatic or the door will close too far? Todd

 

Confusion for starters. Wired it for auto only, both relays click, and then the motor turns clockwise. Not possible if you wired it right. As long as both relays are on or both are off, the motor can't move. We should work on that first.

Second, the nightwatchman is responsible for suppressing the path from the transistor to the coil of the lower relay (on the drawing) and it is responsible for suppressing the transistor current to the upper relay (on the drawing) during "night". It needs to be there for this to work in the end.

"When in the closed position, there is no limit switch in the path". Clearly a misunderstanding.

I'd say, disconnect everything left of the limit switches (except the 20 amp power line to the relays) and manually apply power to one limit switch at a time until you get one relay to click on, the motor moves, hits the limit switch you just applied power to and stops...then apply power to the other limit switch, watch the motor go the other way, open the second limit switch and stop. This eliminates all logic functions and forces you to get the motor and limit switches wired correctly.

 

I just came back in and need to get ready for work tomorrow. I'll have to work on this Monday morning when I get home. Sorry for the delay. On one real quick note, the motor has a breaking action when stopped as it is wired currently. It will literally shake the unit when power is cut. If you run it directly from a battery, the motor will slow down quick but not immediate and the unit barely moves. What I meant by not haveing a limit switch on the close leg is that when I move the 3 position switch (open/auto/close) to close, it cuts out the limit switch and powers the relay coil directly as I read it. Todd

 

ok. First thing I spot is the wiring diagram where I connected the manual "close" wire after the limit switch. My bad.

(fixing drawing....)

NOW remove everything left of the limit switches (except the power and grounds to the relay contacts) and apply power to the left side of a limit switch to get the motor to run each way until it opens the limit switch you are powering and opening that limit switch stops the motor.

The vibration seems to be coming from the MOV on the motor. Remove it and see if the motor behaves better.
I think I'm going to have to put some steering diodes in that to stop the back-feed.
After reading your posts real slowly, I suspect that the light on the nightwatchman is an indicator that power is on its output terminal, and that will activate the transistor (bad). What? Didn't you notice the light was on when you did the test with +12 to the relay and the relay to the nightwatchman output? Never mind. We'll fix it as we learn.

The labels on the 3 way switch were backwards. Diodes 1 and 2 are just to stop the LED in the nightwatchman when you go into manual mode. The other 3 diodes stop backfeed during (geeze!) all the different conditions of: night and manual switching to day, day and manual switching to night, manual switching if the transistor goes bad, night and switching to manual night, day and switching to manual day, manual day and switching to automatic, manual night and switching to automatic. That 3 way switch is enough to make me dizzy!
ps, the diodes can be in the 1N400x series. Theoretically, any diode in that series will work but the higher the number, the better, 1N4007 being the best of them, and usually the same price as any other in that series.
I hope I got it right.
Expecting you back Monday.

 

Wow. The motor doesn't vibrate, when it turns, it moves quite smoothly. It is actually a braking of the motor. It rocks back and forth (the unit is out of the window mechanism and laying on the work bench) from the torque of a braking stop. When ran outside and independent of our circuit, it isn't braked and will stop very quickly but not a braked stop.

 

You can run the motor with or without the MOV. The only thing it will wear upon is the contacts in the relays, and they were made to do this job for years and years. The other 2 MOVs protect electronics we know about and electronics we don't know about. Good thing relays don't vibrate as much as a motor

 

Ok, here we go. I unsoldered everything, cleaned the components, bought a box of 10 1N4007 diodes from RS and a new PC board (didn't want to take the time to clean). I have rebuilt everything to the right of the limit switches; I left in the MOV on the motor. When you touch the open coil + to 12v the motor turns CW. when you touch the close coil + to 12v, the motor turns CCW. This part works beautifully even though the motor still rocks from the sudden torque of being electrically braked. THis breaking action: is it harder on the motors gearcase or the relays. I'd rather replace a relay than the motor and gearcase. The funny thing is that the motor only jumps when it is powered through the relays with the MOV, it doesn't when you simply connect it direct to a power source. I'll go back out and remove the MOV and see what happens. Now, here are a couple of questions before I start soldering other components into place so we know that I am on the same page as you guys. As I understand it, resistors and MOV's are non-polar and may be wired in in either direction, correct? The bipolar transistor and the diodes are polar and may not be wired in either direction but rather only one way to get the desired effect, correct? Assuming that the statement about the diodes and BP transistor are correct, using your last diagram and holding the transistor over the diagram with the legs protruding to the left and the flat face facing down; are the legs to be soldered as shown (top leg to the switched 12v, the middle leg to both the resistor and the "close" side of 3 position switch and a feed from the output side of the night watchman and the close limit switch? I didn't include any diodes just to make this simpler for me now. The diodes will be included in the actual circuit. One more question before I go for the moment; on the subject of the diodes, I take it that the power flows from the back side of the triangle through to the point with the perpendicular line and not the other way, is this correct? Thanks a million, Todd

 

I'm here. I'm reading.

Yes. Try the motor without the MOV on it. (I already said that in post#74.)
Yes, Resistors and MOV's are non-polar.
Yes, transistors and diodes are polarized.
The diodes have a stripe on them that corresponds to the straight line in the symbol for a diode.
I'm going to have to look up the transistor diagram.

 

I removed the MOV on the motor and it made no difference. The braking effect is apparently coming from the relays. Not a big deal, I don't think, just an observation. I replaced the MOV in the motor circuit. Todd

 

Good enough. You determined that the MOV isn't hurting anything. Leave it in and the relays will last longer.

The MOVs on the relay coils have no connection to the motor, they just keep the relay coils from kicking back at the nightwatchman and the transistor.

Exactly which transistor got shipped to you? With or without a "c" on it?
Can you read the pictures on this datasheet?

I see it now. When the driving relay falls open, it is grounding the other end of the motor, completing a short across the motor. I can't easily see how to fix that with a reversable setup like this. I'm getting ideas, but it isn't simple. We'd have to go into H-bridge configuration with 4 relays. Can you live with the way it is?

 

I went out and got one of the transistors. It is the one you had me order, no C. It is the KSP2907A and it also has a little -A49 just below the number. I know that the relays shouldn't be causing the braking effect but they are the only difference between having and not having the effect. oh, well.

 

I see it now. When the driving relay falls open, it is grounding the other end of the motor, completing a short across the motor. I can't easily see how to fix that with a reversable setup like this. I'm getting ideas, but it isn't simple. We'd have to go into H-bridge configuration with 4 relays. Can you live with the way it is?

Can you read the drawings in the datasheet? They describe the pins of the transistor.