I was wondering if someone could offer me some advise on a
project I'm working on. The timer on my washing machine went out and I have
tried to replace it with a Basic stamp controlling some sainsmart relays.
The Stamp seems to be controlling the relays properly
assuming that the LEDs on the relays are indicating that they are being
switched on and off properly. As far as I can tell the washing machine should
be running but its doing nothing at all. If my wiring connections were bad I
would think the results would have been more serious such as setting the
washing machine on fire or electrocuting myself. Since neither of those two
events have occurred I'm assuming that my wiring is OK. This is the information
I had to try and create this thing.
The timer motor is
no longer present because its function has been replaced by the stamp. Is this
causing a short in my circuit? I'm thinking that all this is doing is causing
me to switch some of the relays that are actually no longer necessary. If I
jump from the SW to the TM that would make the same connection as if the timer
motor was still present. I don't see where that is necessary. If I'm missing
something and it is needed would it be reasonable to just jump between them at
the connection where my relays attach to these two? Any other ideas on what
might be wrong?
The timer had a piece where the LI connected to the SW that
was physically broken off so I think that was why it quit working. The lid
switch was functioning as far as I could tell before it quit and I wouldn't think
that switch and the timer would both fail at the exact same time but of course
it is a possibility that would actually give these results.
It is an interesting challenge, but you really need to completely understand the timer in order to replicate it with anything. It is not a simple device.
Doesn't it control all the cycles? Soak, spin, wash, and maybe a fill cycle?
You are going to have to have an override switch on each relay to confirm you are getting the right functionality out of them BEFORE you deal with the BasicStamp as a cycle controller.
Personally, I would use Forth in a Propeller to get a really flexible washing machine controller with remote RS232/RS422 access. But that is just me.
++++++++++
To repeat, whenever you are setting up a bank of relays to eventually be controlled by a microcontroller, it is best to have a switch that will allow a manual powering of each relay coil as a test override.
It confirms your wiring is okay. Eventually the relays might fail, and the same override circuit will confirm that failure and allow you to quickly replace relays.
Without such a feature, you end up second guessing where the problem is. And in some instance, the manual override can assist in an emergency foul up.
I wish the forums were more collabtative and less critical. I am a programmer and not an electrical engineer and that is why I am asking for advise making sure that the basic electrical knowledge I have is enough, I see how the timer functions and believe I understand it properly but I don't know what it is I might not know, Using a propeller for this project would be like using a heavy sledge hammer to drive a small tack. I think if you look at the wiring diagram attached to my first message it will answer your questions about how the timer works.
P'raps Loopy was being ironic in suggesting using a Propellor.
Here is how I would troubleshoot the problem. Fiddle your Stamp program to energize, say, a water value. Now, using the schematic and wiring diagram, trace, beginning at L1 and N, looking for 110V. Work your way toward the valve until you don't get 110 anymore. That should give you enough info to know where the problem is. Repeat as needful.
I was looking into having a Propeller controlled system for a sailboat and it became obvious that when at sea one needed to have an immediate means to overcome any failure in an automated electrical system. After all, in the middle of a typhoon you may not survive to get a second chance.
The suggestion of a Propeller was because Brodie's original Forth tutorial starts out with an example of how to control a washing machine. So I have spent a lot of time imagining how to program a washing machine in Forth to perform all sorts of enhanced cycles. Forth cannot be done on a BasicStamp.
I didn't mean to be unkind, but my level of annoyance with other things is quite high right now. I am feeling I best shut up and not say anything or I will just sound hostile to all.
I've done some work on washers, complicated buggers.
I'd start like this: On a normal load, first thing is water flows. There is usually a large and small load setting. Once full agitation begins. So, start with getting the water valve to open and turn off when full. Use jumper wires to step through the cycle. Don't forget that there are interlocks, like the lid closed switch that may have to be bypassed.
When you get to spin, be careful. There is usually a second winding for the motor on a centrifical switch that kicks the motor into a higher speed once enough water has been shed and the tub builds up speed. Engage this at the wrong time and you will smoke the winding.
Once you can step through the cycle manually you can start to substitute relays for jumper wires.
Good luck and have fun!
JOnathan
Thanks all Sorry if I sound a bit harsh. I'm not a fan of using the propeller for everything. If you need multi- core(cog) its the only way to go ( say for controlling a drone) but for an application that's logic flow is straight linear (as most application are) it has some issues. Wasting 7 of the 8 cogs is well... just wastefull. Programmers (including me) never document anything well. Basic and all its varieties such as PBasic are much more self documenting than C or Spin. The other great advantage of the propeller is very precise high speed timing. Also most applications don't really need this when it comes right down to it. If you really want to hear me go off on a rant check out some of my old threads. ( This is an oldie but a goodie http://forums.parallax.com/discussion/155649/the-state-of-the-world-and-computers-etc/p1 )
Now back to our regularly scheduled program errr I mean thread ...
I think I have found the solution to my problem although I haven't had enough time off from my other job to try it. If someone who has much more electrical experience reading circuit diagrams could check out my theory before I put it to the test I would appreciate that input. I'm pretty sure that not having the timer motor present is causing a break in most if not all of the circuits. My original thought was that switches 8 and 10 only turned the timer on and off which is now no longer necessary. Upon close inspection I am pretty sure that they are also completing almost every circuit in the washer. I think that no connection where the timer motor was originally is causing me to not have power to most of the washing machine functions.
Hi
It looks as though you have built the relay interface to your wash machine timer unit.
In a past life, I have attempted to do Drum Controller operations converting them to
Industrial PLC computers.
The 1st thing I do is to make sure relays are connected for each function.
Then, I set up the PLC or microcontroller to turn them on or off.
I start with very basic, super simple program loaded into PLC or microcontroller.
With the Very Simple program loaded, I run it to confirm that each relay is operating properly.
Changing from an appliance manufactured drum controller can be very complicated and
also very confusing.
It is always best idea to make sure your relay controlled devices are operating as expected before
setting up your clock.
After all, Its a drum controller.
I'm hoping that you benefit from my comments here.
Garyg
L1 is where the 120 VAC comes in, and is presented to the rest of the circuit through the push - pull switch which is part of the timer. With the timer removed the switch is no longer there and L1 is blocked (no power). you need to jumper L1 over to SW, probably through a relay. That washer motor pulls some serious amps, I hope your relays are up to it.The timer motor circuit does not complete a circuit for anything else, just the timer motor itself.Timer switches 8 & 10 do just what you said, turn the timer off and on like for a soak period.
I think you may have hit on the problem. I was thinking L1 was connected to sw through relay 0. I think that would be after were the circuit is expecting the push pull switch thogh.
Ok I tested across the terminals of relay 0 and get no voltage. I have the washer plugged into a switched outlet as a fail safe so I can cut power to the washer. If I have the washer unplugged I get nothing from L1 to 7N as expected. If the washer is plugged in to the outlet but the outlet is switched off I should also get nothing from L1 to 7N but I get a reading of 90 volts. If I use the switched outlet on the dryer it turns the dryer off and on as expected. I may need to give up on this project but I don't really want to. Oh and by the way the dryer is heated by gas not electricity so it doesn't run on 220 as an all electric dryer would. Testing the outlet itself with my meter shows 11 volts switched off and 120 switched on.
Just to elaborate a bit more on my view on relay safety...
If you are going to deploy relays, it is best to have a set up where you can quickly replace them like burn out light bulbs. So I always lean toward socketed relays.
If your machine or home control set up has anything that might be damaged from contacts being stuck on or off, provided a manual switch override on the switching side of the relay will immediately eliminate the stuck or failed relay to allow you time to recover.
If you have a manual switch to power the coil side of the each relay, testing and override can be done for only powered coil positions. That may be good enough in some cases.
I know this adds a ton of switches into the circuit design. But for critical machinery or a sailboat, all these extra bits will be much appreciated.
++++++++=
In the confusion of the new forum format, I didn't realize this was located in the BasicStamp section.
When you say "relay 0" are you referring to the switch labelled "Line Switch" or to a relay that is on your circuit board?I think at this point you should check for solid continuity from the power cord plug to the L1 AND N terminals. With the washer plugged into a live outlet you should read around 120 VAC between L1 and N.
Have you completely removed the timer block or are you connecting your relays to the timer block? Please say it is not the latter!
Also, you might look into why you are reading 90 volts on a circuit that is switched off. It could be that the switch is on the neutral line of the outlet which is never good.
The Block - Timer, timer Motor, and on off bush button are gone. By relay 0 I am talking about the first relay that is wired at the wiring harness that used to connect to the timer block. I am testing at my relays which are all wired in at the point that used to be thew wiring harness for the timer. in the diagram it is the SW to L1 at he top of the page.
I'm good from L1 to 7N but I may have the relays wired backwards. This is the diagram above my relays. I tried to get answers from sainsmart but they offered no help at all, just pointed me back to their very brief description of the product.Is this Diagram depicting the state of the switch when the relay is on or off (like I thought). The text is my interpretation of the diagram only the diagram appears on the relay.
The relay has what is called a single set of class C contacts, which, as your diagram shows, has a common (1), normally open contact (3) and a normally closed contact (2), where "normally" means the relay coil is not energized. I would verify with an ohmmeter that the contacts depicted on the board are as indicated. On the Sainsmart web page is a picture of the schematic and it shows a different configuration on the relay terminal block.
From the ohm meter it appears that 2 is common 1 is NC and 3 is NO. That is consistent with the little footnote on the sainsmart page so I'm going to swap 1 and 2 on all my relays. That should (I hope) make it work.
I believe you want to use the Normally Open contacts. If you wire everything to the normally closed contacts all hell is gonna break loose when you plug it in.
I got everything where I think it was working correctly for the part I built but it appeared that the full/empty switch was not working and perhaps even the motor so I had to give up and buy a new washer. I think I will have a pretty good christmas light timer though for the holiday season.
MarkCrCo
Posts: 89
Comments
Lots of switches in a timer could be replaced by lots of relays, is that your project?
I was wondering if someone could offer me some advise on a
project I'm working on. The timer on my washing machine went out and I have
tried to replace it with a Basic stamp controlling some sainsmart relays.
http://www.sainsmart.com/8-channel-dc-5v-relay-module-for-arduino-pic-arm-dsp-avr-msp430-ttl-logic.html
The Stamp seems to be controlling the relays properly
assuming that the LEDs on the relays are indicating that they are being
switched on and off properly. As far as I can tell the washing machine should
be running but its doing nothing at all. If my wiring connections were bad I
would think the results would have been more serious such as setting the
washing machine on fire or electrocuting myself. Since neither of those two
events have occurred I'm assuming that my wiring is OK. This is the information
I had to try and create this thing.
http://www.manualslib.com/manual/874524/Maytag-Lat2300.html?page=153
The timer motor is
no longer present because its function has been replaced by the stamp. Is this
causing a short in my circuit? I'm thinking that all this is doing is causing
me to switch some of the relays that are actually no longer necessary. If I
jump from the SW to the TM that would make the same connection as if the timer
motor was still present. I don't see where that is necessary. If I'm missing
something and it is needed would it be reasonable to just jump between them at
the connection where my relays attach to these two? Any other ideas on what
might be wrong?
The timer had a piece where the LI connected to the SW that
was physically broken off so I think that was why it quit working. The lid
switch was functioning as far as I could tell before it quit and I wouldn't think
that switch and the timer would both fail at the exact same time but of course
it is a possibility that would actually give these results.
Doesn't it control all the cycles? Soak, spin, wash, and maybe a fill cycle?
You are going to have to have an override switch on each relay to confirm you are getting the right functionality out of them BEFORE you deal with the BasicStamp as a cycle controller.
Personally, I would use Forth in a Propeller to get a really flexible washing machine controller with remote RS232/RS422 access. But that is just me.
++++++++++
To repeat, whenever you are setting up a bank of relays to eventually be controlled by a microcontroller, it is best to have a switch that will allow a manual powering of each relay coil as a test override.
It confirms your wiring is okay. Eventually the relays might fail, and the same override circuit will confirm that failure and allow you to quickly replace relays.
Without such a feature, you end up second guessing where the problem is. And in some instance, the manual override can assist in an emergency foul up.
Here is how I would troubleshoot the problem. Fiddle your Stamp program to energize, say, a water value. Now, using the schematic and wiring diagram, trace, beginning at L1 and N, looking for 110V. Work your way toward the valve until you don't get 110 anymore. That should give you enough info to know where the problem is. Repeat as needful.
I was looking into having a Propeller controlled system for a sailboat and it became obvious that when at sea one needed to have an immediate means to overcome any failure in an automated electrical system. After all, in the middle of a typhoon you may not survive to get a second chance.
The suggestion of a Propeller was because Brodie's original Forth tutorial starts out with an example of how to control a washing machine. So I have spent a lot of time imagining how to program a washing machine in Forth to perform all sorts of enhanced cycles. Forth cannot be done on a BasicStamp.
I didn't mean to be unkind, but my level of annoyance with other things is quite high right now. I am feeling I best shut up and not say anything or I will just sound hostile to all.
I'd start like this: On a normal load, first thing is water flows. There is usually a large and small load setting. Once full agitation begins. So, start with getting the water valve to open and turn off when full. Use jumper wires to step through the cycle. Don't forget that there are interlocks, like the lid closed switch that may have to be bypassed.
When you get to spin, be careful. There is usually a second winding for the motor on a centrifical switch that kicks the motor into a higher speed once enough water has been shed and the tub builds up speed. Engage this at the wrong time and you will smoke the winding.
Once you can step through the cycle manually you can start to substitute relays for jumper wires.
Good luck and have fun!
JOnathan
Now back to our regularly scheduled program errr I mean thread ...
I think I have found the solution to my problem although I haven't had enough time off from my other job to try it. If someone who has much more electrical experience reading circuit diagrams could check out my theory before I put it to the test I would appreciate that input. I'm pretty sure that not having the timer motor present is causing a break in most if not all of the circuits. My original thought was that switches 8 and 10 only turned the timer on and off which is now no longer necessary. Upon close inspection I am pretty sure that they are also completing almost every circuit in the washer. I think that no connection where the timer motor was originally is causing me to not have power to most of the washing machine functions.
Here is the link to the wiring diagram again:
http://www.manualslib.com/manual/874524/Maytag-Lat2300.html?page=153
The input of anyone who has the time and expertise to check this for me would be much appreciated.
It looks as though you have built the relay interface to your wash machine timer unit.
In a past life, I have attempted to do Drum Controller operations converting them to
Industrial PLC computers.
The 1st thing I do is to make sure relays are connected for each function.
Then, I set up the PLC or microcontroller to turn them on or off.
I start with very basic, super simple program loaded into PLC or microcontroller.
With the Very Simple program loaded, I run it to confirm that each relay is operating properly.
Changing from an appliance manufactured drum controller can be very complicated and
also very confusing.
It is always best idea to make sure your relay controlled devices are operating as expected before
setting up your clock.
After all, Its a drum controller.
I'm hoping that you benefit from my comments here.
Garyg
If you are going to deploy relays, it is best to have a set up where you can quickly replace them like burn out light bulbs. So I always lean toward socketed relays.
If your machine or home control set up has anything that might be damaged from contacts being stuck on or off, provided a manual switch override on the switching side of the relay will immediately eliminate the stuck or failed relay to allow you time to recover.
If you have a manual switch to power the coil side of the each relay, testing and override can be done for only powered coil positions. That may be good enough in some cases.
I know this adds a ton of switches into the circuit design. But for critical machinery or a sailboat, all these extra bits will be much appreciated.
++++++++=
In the confusion of the new forum format, I didn't realize this was located in the BasicStamp section.
Have you completely removed the timer block or are you connecting your relays to the timer block? Please say it is not the latter!
Also, you might look into why you are reading 90 volts on a circuit that is switched off. It could be that the switch is on the neutral line of the outlet which is never good.