I'm trying to use my EZ-8 to trigger a relay and can't get it to work. The board works great when hooked up to an LED for testing. I'm using the 12V wall wart that is recommended for the board and am getting 13.71V at the plug. However I can't get it to fire a relay. When I program a long "on" cycle into a channel and put a a meter between V+ (positive) and OUTx (negative), I only get about 9V.
I ordered a new ULN chip and replaced the one on the board and get the same results. I've tested my relay circuit and it works fine when connected to a fully charged 9V battery.
Any thoughts on a solution?
Sounds to me like you have an unregulated or bad power supply. With a good 12v PS you should be getting 12v between V+ and OUTx. You should also be getting 12v (or just slightly above) at the plug.
Something is amiss. I connected a WickLED to an EZ-8 (you need to measure across a load) and got 11.5v when operating with a 12.2v input (which make sense as the load was only about 20mA).
I got the power supply from EFX that was supposed to be the right one. I am getting over 13V at the plug but losing over 4V at the output. Would using a regulated 12V power supply give me the usual drop of around 1V to the output?
Any other thoughts on what to try to fix the problem? This controller is running several props that lead to my front door where the TOTs come to get the candy. The main path in my display has been turned into a bunch of static props as I need to control the relays in order to get them to run.
I'm still struggling with "losing over 4v at the output." When you're measuring at the output, is it with some kind of load connected? (e.g., the relay)
That may be my problem as I wasn't measuring it under load. Maybe it's a bad relay after all.
With 12.2v going in and no load, I get 11.4v between V+ and OUTx. Something is wrong other than your relay. You stated in the first post that your relay works fine when connected to a 9v battery. Although there are exceptions, most 12v relays won't work on 9v. At any rate, you stated your relay works. What's the mA draw of your relay? How many relays do you have connected (or plan to connect) to the Prop-1?
I'll measure it under load tonight when I get home.
The relay I'm using is a 5A. I was hoping to use 3 or 4 relays. Maybe using the EFX relay board will solve the problem.
You need to ensure that the coil current is 200mA (or less) when activated -- that would be about 2.4W.
QuoteThe relay I'm using is a 5A.
I think you're confusing the contact rating with the mA draw of the coil. You need to find how much current (mA) the coil of the relay needs to operate.
Jack has a good pont. You need to find how much current (mA) the coil of the relay needs to operate.
Here's how you find out how much mA the relay coil draws.
1) Connect volt meter in series with the lead on one side of the coil and connect the other lead to other side of the your power supply, then make sure that the other side of the of the relay coil is connected to the power supply. Make sure your volt meter is set on mA. This will tell you how many mA relay coil is drawing.
2) Look at the top of the relay for the manufacture's name and get on there web site, were you should find the data sheet for that relay model.
I done this alot in the 21+ years as an control electrician. As, I say practice makes perfect ;D
You're right. I'm still new to this and trying to make sense of it all. I'm using a OMI-SS-212D, 12V, 5A relay. The datasheet is at http://relays.tycoelectronics.com/datasheets/OMI-2P.pdf If I'm reading it correctly, it's 60mA which is within the range noted.
I checked the EZ-8 with a constant on and the relay attached and it read 13V so I'm thinking this is not a problem with the board but with the relay.
I would suggest you to try another power supply and I am thinking that the power supply maybe bad. I have one question for you... What is the size(in amps) of the power supply, you are using?
Quote from: bsnut on October 04, 2010, 07:12:07 PM
I would suggest you to try another power supply and I am thinking that the power supply maybe bad. I have one question for you... What is the size(in amps) of the power supply, you are using?
I got the power supply from EFX. It's a 12V 1000mA supply that's supposed to be for the EZ-8/
What else are you trying to power, besides the relays?
What, I would use is a good relay that you know that works and test with the power supply that came with the EZ8. Once you know it works with that power supply, then I would test the other relays with the EZ8 with a long pulse. Do this test with all same relays to find any bad relays.
Remember when you load down any power supplies, the voltage will drop down to what the power supply voltage is.
Quote from: halstaff on October 04, 2010, 06:54:07 PM
You're right. I'm still new to this and trying to make sense of it all. I'm using a OMI-SS-212D, 12V, 5A relay. The datasheet is at http://relays.tycoelectronics.com/datasheets/OMI-2P.pdf If I'm reading it correctly, it's 60mA which is within the range noted.
I checked the EZ-8 with a constant on and the relay attached and it read 13V so I'm thinking this is not a problem with the board but with the relay.
You have a DPDT relay which has 8 pins. Are you sure you have it wired correctly? V+ and OUTx from the Prop-1 should be connected to
1 and 5 on the diagram. 3 and 4
or 7 and 8 should be connected to whatever you are trying to activate.
With 1 and 5 on the relay connected to V+ and OUTx you should hear and feel a slight "click" of the relay when the Prop-1 is triggered. If you are still having problems it would be helpful to know exactly how you have the relay connected to your prop.
I decided to make one more attempt at getting this working before putting the props that were relying on this away until next year.
I have this connected as you indicate. Here is a photo -
(http://i922.photobucket.com/albums/ad69/Halstaff/EZ8Hookup.jpg)
I tried the relay suggested in another post regarding using relays with the EZ8. It is a Radio Shack 275-218. The specs are as follows -
Max. power - approximately 1.08 watts
Nominal coil voltage: 12VDC
Nominal coil current: 75mA
Coil resistance: 160 ohms +10%
Pull-in voltage: 9.6VDC max.
Dropout voltage: 1.2VDC min.
Contact rating: 10mA at 110VAC or 24VDC
Maximum operating voltage: 250VAC/125VDC
Minimum load: 100ma, 5VDC
I hope you can tell me I made some rookie mistake and this is easily fixed.
Thanks everyone for all the help and I hope you have a great Halloween!
Steve
Just so we're clear, everything is working now -- right?
Quote from: JonnyMac on October 18, 2010, 10:29:42 AM
Just so we're clear, everything is working now -- right?
No, unfortunately not. The relay will not trigger. Hopefully it's my set up that's faulty.
According to RadioShack those are in stock at my local stores -- I'll get one and give it a try.
Thanks. Any help you can give me would be greatly appreciated.
Well, its kinda hard to make out exactly whats what in regards to the relay in that photo. It certainly doesn't match the specs that you gave a link to (which is where I got the diagram in my previous post). I have no idea what the pin outs are for the relay in your photo. It appears that you have line voltage connected to a pair of terminals on the relay. If this is the case I'm assuming you have it exposed just for photo purposes, BE VERY CAREFULL WITH THIS! I would suggest disconnecting the line voltage from the relay and use a meter to test for continuity between the N.O. and N.C. contacts and then test again with a 12v battery connected to the coil. I'm still unsure of how many different relays you have tried. One bad relay is certainly possible but if you have tried other relays with the same result then its likely that the problem is elsewhere.
Yes, this is a different relay than I had originally used. It was suggested in another post in regards to using relays with the EZ-8. I did have my other relay hooked up as you posted and still couldn't get it to work right.
You need to check the relay function as I outlined in the last post, no EZ-8, no line voltage. Use a separate power supply and check the N.O. and N.C. contacts. If the relay works then something is wrong with the wiring or the programming.
From, what I can see in the photo, it looks like the white wires are hooked up on the wrong contacts on your relay.
What, you need to do is disconnect the wires that you have on the relay and do this test. Take a meter and set it to continuity (ohms) . With the relay off. The goal of this test, is find which contact is Normally Close and Normally Open.
Take one of the leads from your meter and place it on the blade on the bottom row (second from the right in your photo) on the relay, which should be common point of the relay. Now take the other meter lead and touch the blade on the far left (bottom row in photo) . You should see continuity and hear beep sound if your meter is setup that way. This will be the Normally Close contact (blade) on the relay when the relay is off.
Now move that same lead, to the contact next to the one you just touched and you will see nothing on the meter. This will be the Normally Open contact.
Now, for the second part of the test will tell if the relay is working. When you power the relay up, with voltage on the coil, you will see continuity on the meter, when Normally Open contacts are close. And, when you remove voltage from the relay coil, you will see no continuity on the meter.
Remember, most of the relays that are manufactured follow two numbering schemes. These numbering schemes are Ocal and Blade. The relay that you have is a Blade type.
I've figured out which terminals are the NO and NC but that is not the problem. The relay will not respond to the input from the EZ-8. It works fine when connected to a new, fully charged 9V battery. This relay is an ice cube model so you can see as well as hear the relay engage. However when hooked up to the EZ-8 and the program is started, there is no response from the relay. When the program is engaged, I'm only getting about 9.5V to the relay.
OK, that is good.
All relays have pick up time around 20ms and drop out time around 10ms. If, you are using Vixen to program the EZ-8, you need to program your event timing above the pick up and drop out times for the relay that you plan to use.
Now, that is covered. I would make sure that you have a good ULN with no pins clipped.
If you are trying to power the whole show with 9v battery or power supply it maybe your problem. I would power your show with a 12vdc @1000mA power supply. The relay that you have should work with 12vdc with no problems.
QuoteIt works fine when connected to a new, fully charged 9V battery. When the program is engaged, I'm only getting about 9.5V to the relay.
I'm confused with these statements. If the relay works with a 9v battery why won't it work with 9.5v? I don't have an EZ-8 but it doesn't seem right that you are only getting 9.5v out when there's 12v going in. Have you tried an LED in place of the relay to test the EZ-8 program? If it lights an LED when its supposed to then something has got to be wrong with the EZ-8.
It does work with an LED.
Quote from: halstaff on October 19, 2010, 05:15:17 PM
It does work with an LED.
Where is this LED connected? If it is connected to the TTL output headers, then the LED will work if the LED is size for 5vdc.
I think you might have a duff power supply. You should certainly see more that 9.5v on the output, I measured and verified. And to Jack's point, if a 9v battery can activate the relay, then 9.5v out of the board should... unless it's a bad power supply and under any kind of load goes limp.
Well I tried another 12V power supply and still nothing. I measured both power supplies and am getting a good 12V from each at the plug.
This, is how I would troubleshoot the EZ8.
Do you have 12vdc between V+ and GND when the power switch is set in position 2? If you have 12vdc this means your relays or 12vdc LEDs should work. You need to make sure that the EZ8 isn't touching any conductive surfaces, that could cause the power supply to shut down.
I suggest you to do this next test, to see if EZ8 ULN is working like it should. This means, you will need delete the old program that you have.
What, I am suggesting you do, is program Channel 0 to be on for 5 seconds or more. This should give you time to put a meter between V+ and Channel 0. If you see 12vdc between V+ and Channel Output 0 with your meter and it turns off after 5 seconds, this means ULN is working correctly.
You will need do this test for all of the channels on the EZ8. That way you can see that all the channel outputs are working correctly. If, you don't see 12vdc on Channel Output 0 or any other Channel Outputs, you will need to replace the ULN with a new one. If you want you can use a relay or a 12vdc lamp when doing the rest of this test.
Good idea but I've already tried that. I even ordered another ULN chip from DigiKey and replaced the original one and it still wont trigger the relay.
Keep in mind that a meter applies virtually no load when measuring voltage so this is not a valid stress test. If you plug 12v into the EZ-8+ and only measure 9.5v between V+ and GND then there is a problem with the board (which should be smoking) or the power supply.
Fortunately, the boards not smoking and I tried 2 identical power supplies that I got from the order RMG placed for the June gathering. I've used 2 different ULN chips so that probably isn't the problem either. I've tried several different relays. So if it's not the board, power supply, relay or chip that leaves me. I must be doing something wrong but I don't know what else to try.
Thanks everyone for all the help but it looks like this project will be put off until next year. I hope everyone has a great Halloween!
As a last ditch effort try programming two channels of the EZ-8 identically for the relay. Connect both channels to one side of the relay coil and the other side of the coil to V+.
I was editing my post when you posted what you did.
Are you setting the board on any conductive surfaces? It sounds like to me the power supply is bad or it doesn't have enough mA to do what you want to do.
Jon is right, when measuring voltage, it is not a valid stress test. The goal is to see that the ULN is doing its job and using a 12vdc lamp or relay to do the rest of the test was a way to test without a meter.
I, would suggest you order a 12vdc @ 1000mA plug in power from Jon and its sized for what you need to do.
I have 2 power supplies that I got from Jon that are supposed to be for the EZ-8 and I'm not having any luck with either of them.
Quote from: JackMan on October 20, 2010, 07:25:32 AM
As a last ditch effort try programming two channels of the EZ-8 identically for the relay. Connect both channels to one side of the relay coil and the other side of the coil to V+.
I thought that might work but still nothing from the relay. I guess I better not get in any disagreements with kids as I'm certainly not smarter than the 8 year old that was able to make this work.
I am wondering what is the no load voltage(open circuit) of your 12vdc power supply is? 12vdc plug in power supplies, put out around 15vdc in open circuit for a 12vdc power supply.
My, thinking is that the power you have is mismarked from the manufacter and you will never know untill you power it up with a load and check it with a meter. If it is a 9vdc power supply, they put out around 12vdc in open circuit for a 9vdc power supply.
I do not understand, you are saying it is not ULN and I can't see why are having problems. I only blue smoked one pre EFX-TEK product the RC4 and that is because I hooked up the servo cable wrong ;D. I shorted power supplies before and they just shut down and when I remove the short the power supply returns to normal.
Take a voltage reading at the relay coil connections when the EZ-8 is running the program and the relay should be energized and let us know what you find. If you are getting 9.5v at the relay coil, I'm stumped as to why its not pulling in if it works with a 9v battery.
Alright, since you guys refused to give up on this, I continued on and have solved one mystery. I put my meter on the 9V battery when connected to the relay and was getting a reading of over 15V. Now I enough to know that's not right. Changed out the battery in my meter and low and behold I get a reading slightly above 9V, right where it should be. So I reconnected the relay and ran the steady state program to get a good reading and am only getting 6.4V. I apologize for such a newbie mistake which resulted in bad info. No way can I expect you to help solve the problem if I give bad numbers.
However, that still doesn't solve the problem of the relay not operating with the EZ-8. I've tried 3 different relays, 2 power supplies and 2 ULN chips. I've connected the relay both in NO and NC positions with no change.
I tested the relay with some partially depleted 9V batteries and found it won't work with 7.85V but will with 8.5V. If I now have the readings right, the problem seems to lie in the fact that I'm only getting about 6.4V to the coil of the relay when attached to the EZ-8.
What am I overlooking? And where's that 8 year old so I can have him show me what I'm doing wrong now?
Steve
QuoteAnd where's that 8 year old so I can have him show me what I'm doing wrong now?
So you want 8 year old to program and troubleshoot it. I think Jon charges extra for that ;D.
When, I troubleshoot control system at my work or at home, I start at the beginning. And that is the incoming power supply. I will check to see if the voltage is right. In your case, a 9 volt battery doesn't have a enough mA to run your relay. That is the reason why the battery voltage is down to 6.4 volts, that because the coil and EZ-8 voltage requlator is causing voltage drop. That's why the plug in power supplies voltage stays around 12 or 11.5 volts, because of the voltage requlator in the power supply keeps the voltage up. Then, if the volage isn't right then I start disconnecting each load (relay or light) one it a time to find the problem.
I don't know why you are using a battery to do your test. This is only good for programming the EZ-8.
We are trying to help fellow prop builder out and I don't like to give up. This also provides useful info to other prop builder to learn from. I will try the relay setup that you have, so I can see what is going on when I get home from work.
Well due to the fact that you guys were still trying to figure this out long after I had given up, it's fixed.
I had been using the 2 power supplies I had gotten from Jon that were for the EZ-8 and were marked at 12V, 1 amp. When I put them under load and checked the reading on the back of the board, they were both only showing 7.5V. Either they are both faulty or mismarked. I was able to pull a regulated 12V power supply from another prop and presto, it works.
Lessons learned - it's better to trust a reliable meter than to make assumptions or believe a label. Also, haunters are the best!
Thanks for all the help and persistence in helping me figure this out. Now it's time to let my inner 8 year old out to get this programed and ready for Halloween. Good luck to everyone with your haunts!
Steve
Well Steve, I'm glad its finally working! Funny though, if you go back to the very beginning of this thread, the 2nd post was me telling you that it sounded like you had a bad or unregulated power supply. ;) Happy Halloween and good luck to you as well!
You guys said it several times. I could have saved a lot of time if I had just thought to verify the readings I was getting from my meter. With the low battery, the readings were showing I was getting the acceptable voltage from the power supplies. Weird how both of them are bad.
Thanks again for all your help. I'm pulling my MIB back out of the shed today and it should be scaring people on Halloween.