Garage door type switch...

[holbrooka]

Thank you so much for your help!!!

I am ordering the stuff now. It probably won't get here until mid to late next week and I will be out of the state for about a month...so this project will, again, be on hold

But at least when I get home I will have all the pieces to finish it up!!!!

I can't thank you enough and I'm sure I'll run into some issue or another.

When I've got it all wrapped up I'll post a picture and maybe a link to a video of the lift working!

whooohoooo!!!!!!

[holbrooka]

Well I am finally there!!!

It has taken much longer than expected or hoped, but I have been working on it as I was able.

(due to some family health issues I had MUCH less time to work on ANY of my projects, but this is now resolving so I am back!!!!)

I made a circuit board for the circuit you gave me, got it all soldered in and am now in the trouble shooting mode!

Here is what I have so far:

When it is not plugged in I have continuity between pin 1 and 3 and pins 4 and 5 on the DPDT. When I plug in the 12v (or 9V) DC transformer I can hear a little click and the continuity changes to pin 1 and 2 and pin 4 and 6. When I unplug the transformer it returns to the 1-3 and 4-5. --That's the good news! Sounds like the switch is working just fine!

Now comes the part where I'm not so sure about... when I push the button... well, no change in continuity..

Here are some images... Any suggestions you have about troubleshooting would be greatly appreciated!!! (I have not yet attached this to AC, as I was wanting to check it for proper operation first--- I don't think that would make a difference... but we know how good my guesses are, don't we! )

[pebe]

Hi Adam,
I’m surprised at your findings. It would appear that when you switch on the relay changes over (ie. the 555 is ‘set’). I would have thought that as C1 is discharged at switch-on, then it would have switched on with pin6 high and the 555 would have been in the reset state. However, a few tests will establish where the problem is.

1. Make sure that the voltage on pins2 & 6 is half the battery voltage.
2. Now short out R1. Pin3 should go low and stay low after the short is removed.
3. Now short out R2. Pin3 should go high and stay high after the short is removed.

If these test prove OK, then the problem is probably that there is not sufficient energy in C2 to change the voltage on pins2 & 6 when the switch is pressed. I originally breadborded the circuit using the CMOS version of the 555, and that has a bigger output swing.

So change R1 and R2 to 100K. To make doubly sure, also change C2 to a 1µF cap. That should fix the problem.

[holbrooka]

Thank you for the suggestions!!!

Here is what I have...

First off, the voltage from my transformer (9vdc 800mA) Reads 12.89 across the terminals on the board.

When I test from Pin 1 to pin 2/6 the voltage reads 10.84
When I test from Pin 1 to pin 3 the voltage reads 11.56

So.. I'm guessing there is a problem right off the bat with pin 2/6 being so high... maybe I damaged the 555 when I soldered it?

I did run the other tests as well in case that assisted with trouble shooting...

Shorting R1 had little to no effect - voltage across 1 and 3 dropped from 11.56 to 11.28, but returned to 11.56 as soon as the short was removed

Shorting R2 caused voltage across 1 and 3 to drop to 5.7 but it bounced back up as soon as the short was removed.

Shorting R1 or R2 had no effect on the DPDT, (continuity did not change between the different pins) but I did think I heard a click when I shorted R2 - but again no change in continuity...

At any rate, I am ordering a socket for mounting the 555 (figuring I did something wrong), so I will order a CMOS 555 while I am at it, that way I can switch them out if it is the case that it is due to the different chip.

I'll post back the results when I get the socket installed and am able to try the circuit with both 555 chips!

Any other thoughts?

And... THANK YOU for all your help!!! You are awesome!!!! I am amazed by how knowledgeable you are about all this stuff and I am have a lot of fun learning how it all goes together. I started looking at the spec sheets for the dpdt and the 555 wondering what it all meant, now, I have an idea about what it all means!

Thanks!!!!

Adam

[pebe]

When I test from Pin 1 to pin 2/6 the voltage reads 10.84
When I test from Pin 1 to pin 3 the voltage reads 11.56

Yes, I think you may have popped the 555. 10.84V on pin6 is more than 2/3 of the supply 12.89, so the 555 should be reset and pin3 should = 0V.

I would definitely go for the modified values for R1, R2, and C2 that I suggested - then it is 100% sure to work.
When you have fitted the holder, check pins2 & 6 = approx 6.45V ( 1/2 of supply) before you fit the 555.

[holbrooka]

Alrighty then!

Since I figured I popped the 555 I just replaced the old 555 with a 555 mount and then inserted a new 555 chip and it seems to work as far as the numbers go and as far as continuity goes....

The pins respond just like you said they would with pin 3 going high or low and staying put until the button is pushed. The DPDT works just fine with alternating continuity between pin 1 with 2 or 3 and pin 4 with 5 or 6. (I did pick up the other resistors and caps like you suggested.. just in case, but so far it seems to be doing good, just as you designed it! AWESOME!!!!

I was hoping to post a picture of the lift in action... but the real world test kind of didn't go so well...

I got a little nervous with not being sure the limit switches were positioned correctly and a little excited when the motor started moving things around and pushed the button a few too many times in rapid succession... the result seems to have been that it fried the DPDT. The whole thing just stopped, no motor, nothing, so I unplugged it and did the diagnostics.

Right now I am waiting for the DPDT to dry (back coating) then I will give it a second shot in the real life testing and let you know how it goes!

I just wanted to give you an update as to the progress!!!

[holbrooka]

Got it all put back together and discovered the dimmer is not working.

I haven't done any trouble shooting with it but I can tell you it sends 120v regardless of the position of the dial....

The specs for this say 500w @ 220v...

The drill draws up to 3.5 amps..... If I guess right the 500w/220v - a little over 2Amps but since I am using the 120v that should give me 4amps... so....

Not really sure what is up with it just yet... If you have any ideas, please let me know.

Adam

[pebe]

Hi Adam,
I think the triac may have popped because it got too hot. You can test it by measuring continuity between input and output. If it reads a short then it's popped. But it's rather surprising because its 'On' resistance is quite small and the original had no heatsink. If the triac does prove faulty, then you should replace it with one of a higher current rating.

[holbrooka]

Thank you for your help on that!!! It was the triac, I got it replaced and things have returned to a state where I was able to test things out and "play" with it a bit.

For my next dilemma.... I have it all wired up but it is not operating as I am expecting (I'm guessing I have it wired wrong!) I have been spending lots of brain power trying to figure it out, but evidently what is upstairs isn't enough to figure this out!

Here is the scenario... I have L2 set on the upper end of the travel and L1 set on the lower end of travel. When I have reached L2 (it becomes open) the lift stops (yeah!). When I push the button the lift begins to descend (L2 closes as it moves away) , moves about 3" down, stops and reverses until it stops again at L2 (L2 open).

If I hold L2 open when I push the button the lift descends about 3 inches and stops, when I close L2, it moves up and stops when L2 is open.

I have tried changing wires, but so far I am unable to find the right combination and I am a little worried about frying things with just trying a different wiring combo...

Any suggestions would be greatly appreciated!!!

And, more importantly than all of this stuff.. I hope you had a happy holiday season and are enjoying the new year!

Adam

[pebe]

Hi Adam,
Looking back at your previous posting on 9 November, I note that in the photo the 555 was fitted the wrong way round. I assume you corrected that.

As the motor changes direction without you pressing the button, it appears that the 555 is toggling between its on and off states, on its own. To be sure that assumption is correct, can you do these tests?

1. Switch off both supplies, ie. the 120VAC supply to the moter and the 12VDC supply to the 555.
2. Operate the motor by hand to get the door half open.
3. Switch on the 12V supply to the 555.
4. Measure the voltage at pin3 of the 555 - if should be low (0V), and the relay will be de-energised..
5. Repeatedly press the push button to switch pin alternately high and low. You should hear the relay clicking.
6. Press the push button until pin3 is low.
7. Switch on the supply to the motor. The door should rise until L2 opens, then the motor should stop.

Can you let me know if that is all OK - or if not, where it goes wrong?

BTW, what values are you currently using for R1, R2 and C2?

[holbrooka]

Hello there!

I'm still here working away as time permits!

A few answers to your questions...

First off... I do not think the 555 is in backwards... if it is that might explain a lot...

As for the testing... I followed you directions to come up with the following:

Disconnected both AC and DC power.

Reconnected the DC Power
Pin 3 (Measured between Pin 3 and Pin Measures 1.39V DC

Push the button

Pin 3 now measures 13.10V.

When pushing the button this continues to flip back and forth.

AC Applied:

Pin 3 is at 1.39V ==> Button is pushed and Pin 3 Volts goes UP to about 12.9, then within less than a second drops back to 1.39V Simultaneously the motor turns then stops turning. Pressing the button results in the same action each time with the motor ALWAYS going in the same direction, never reversing.

I am still using the initial values for R1, R2 and C2 (R1 & R2 = 10K And C2 = 100n)

Some images...
The Motor set-up



The circuit while testing


and



Again, thank you for all of your help! I really appreciate it! (I think these pictures are small enough?)

Adam

[pebe]

Hi Adam. Sorry to hear you are still having problems.

You say the motor always runs in the same direction. Is that even during the brief period when the relay is energised? You had it reversing before, so have you changed any of the connections from the relay?

It is toggling as it should when you press the push switch with no AC applied, so the 555 is working as it should. I think the problem is pin 6 is going high and resetting the 555 when it shouldn't when AC is applied That points to pickup on pin6 either by induction or capacitance from the adjacent AC leads. You can prove it this way.

1. Remove the push button leads from the PC board.
2. Short out R2 for about 3seconds. The relay should energise and cause the motor to run one way.
3. Remove the short from R2 and the motor should continue to run until the limit switch operates..
4. Now short out R1. The motor should reverse until the other limit switch operates.

Can you let me know if that works OK, or at which step it goes wrong?

(BTW. You have a link on the PC board between pin3 and R3 that runs very close to the copper track carrying AC. That link is being affected by the voltage on the AC track, with unforeseen results that could be aggravating the problem. It would be wise to cut out that link and replace it with a wire routed away from the AC track).

[holbrooka]

Okay! Here we go!!!

I removed the trace between pin 3 and R3 and replaced with an insulated bit of wire.

Steps:
1) I disconnected the leads from the push button (I didn't remove them from the board because they are in there funky... but if you think I should I will do!)

2) I shorted out R2 (briefly) and the motor rotated toward L2 and stopped once it got there (I operated the switch)

3) I shorted out R1 (briefly) and the motor rotated towards L1 until I released L2, then the motor reversed direction and rotated back towards L2 (until I operated the switch again)

4) I then shorted R1 BUT I maintained the short and the motor rotated towards L1 even when I released L2, the motor continued until I operated L1 and stopped. It remained stopped when I removed the short on R1.

Hmmm... I really don't know what this means...

[pebe]

All OK except for 3). L2 should have no effect there. To make sure the switches are working as they should, try this. Do NOT operate the switches by hand.

1. Switch off. Put a short across R2 and keep it there.
2. Switch on. Motor should rotate towards L2. and stop when L2 opens.
3. Switch off. Remove short on R2.and put a short across R1 and keep it there.
4. Switch on. Motor should rotate towards L1. and stop when L1 opens.
5. Switch off. Remove short on R1.

If that's OK then the switches are working OK, and the fault is static pickup on pin6 from the AC supply. So alter the circuit like this to give it more immunity from pickup.
1. Remove C2 (100nF) and fit it as CI in place of the 4n7 that is there.
2.Fit a 1µF electrolytic capacitor in place of C2 (ensuring correct polarity). So you now have C1=100nF, and C2=1µF.

[holbrooka]

Testing results:

(First off, the only Switch off position is on the limit switches, the other switch is the d/c momentary on switch)

So... with L1 and L2 closed (in mid position of travel) shorting and holding R1 moves the unit until it hits L1 and stops.

Removing the short on R1 (L1 open and L2 Closed) shorting and holding R2 moves the unit until it hits L2 then stops.

Removing the short on R2 (L1 closed and L2 open) shorting and holding R1 moves the unit until it hits L1 and stops.

So that all seems to work just fine.

I replaced the C1 with the 100nF cap and installed a 1uF cap at C2, I also replaced the relay switch as it failed.

Now... I have the same problem.

With L2 open I push the switch and the unit moves towards L1 briefly, stops then returns to L2. If I hold L2 open and press the momentary on switch it does the same thing. Then each time I press the button it continues to move towards L1 briefly (with L2 held open) - If I do not hold L2 open then it stops travel towards L1 and returns to L2.

Now, if I push the button while it is still traveling towards L1 it stops and if I push the button again it returns to L2.

Is it possible that I have the signal diode in backwards? Would this cause this error? I"m completely flummoxed!

Hope all is well with you! Thank you for all your help!

Adam