jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 (edited) I will be wiring per this diagram: My question is, will I need to use two outputs, one for ground and one power power, both connecting to thecoil on the relay, correct? Edited July 25, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 25, 2010 Author Share Posted July 25, 2010 Okay guys, here is the FINAL diagram for the transistor circuit. Each one of the leads that will go to the relay board will be on opposite sides of the relay coil. Check it over if you will, just want to make sure everything is right, thanks guys!! Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 25, 2010 Author Share Posted July 25, 2010 (edited) Oh for Pete sake, I'm having no success, even with this configuration...DAHHHHHHH!!!! Matt Cramer, please step in Edited July 25, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 25, 2010 Author Share Posted July 25, 2010 Okay guys, here is my final rendition of this wiring scheme. I really hope this works this time, otherwise, I have no clue as to what to do. Let me know what you guys think and whether or not this looks right: Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 25, 2010 Author Share Posted July 25, 2010 (edited) Tested this configuration and here are my findings: Output 1 off: 12.69v DC Output 1 on: 8.09v DC Is this right? In my mind, logically, I would think that when Output 1 is off then it would read 0v DC and when on, it would read 12.69v DC. I'll go out and test this and perhaps invert them so that I get 8.09v DC when off and 12.69v DC when on and see what that does.This is the first time I've ever done anything to the PCB board, so bare with me! Thanks guys! Edited July 25, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 25, 2010 Share Posted July 25, 2010 (edited) Lets look at it how you had it before during your testing. So you had basically zero volts and continuity when it switched on? So you had a working switched ground from megasquirt. So that was working. Now you need that to make it to the negative side of the relays coil, 12v source should come from? Lets leave out the relay board and imagine connecting directly to a relay. All we need to get the relay working is 12v for the other terminal. Like this, This maybe helpful on how to get power to a relay. http://www.msextra.com/forums/viewtopic.php?f=101&t=35256 So relayboard #7 is pin 25 your ground and #8 is the 12v source, that's what I'm gathering from this. Probably should wait for Matt to verify it though. Edited July 25, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 26, 2010 Author Share Posted July 26, 2010 (edited) Your theory is making sense now. I assume that diode is strictly to protect from voltage shooting up the ground? Let's look at this diagram: As of now, I have it wired like so. This diagram is a little more confusing to me because it looks like it wants to feed 12v+ to BOTH side of the relay coil, and my test isn't showing any conclusive evidence that it was working on the bench (I'm looking for 12v when output 1 is on and 0v when off I would assume). I COULD go back to the other way I had it wired, but this diagram was pulled directly off of MSExtra.com and I believe it is a reliable source. Edited July 26, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 26, 2010 Author Share Posted July 26, 2010 Looking at these two diagrams: http://www.diyautotune.com/tech_articles/common_megasquirt_modifications.htm#Add_Output_v3 http://msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#outputs Essentially, the top diagram looks like it is only manipulating power (or ground, not sure whether its grounding or sending 12v+) to the coil positive (or negative). But, the bottom one is showing that it wants to be attached to both sides of the coil, hence my last drawing routing two separate leads out to the relay board. Which one is better? Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 26, 2010 Share Posted July 26, 2010 (edited) Looking at these two diagrams: http://www.diyautotune.com/tech_articles/common_megasquirt_modifications.htm#Add_Output_v3 http://msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#outputs Essentially, the top diagram looks like it is only manipulating power (or ground, not sure whether its grounding or sending 12v+) to the coil positive (or negative). But, the bottom one is showing that it wants to be attached to both sides of the coil, hence my last drawing routing two separate leads out to the relay board. Which one is better? The second diagram isn't saying to use megasquirt for power. It just wants you to have a diode between the ground coming from megasquirt and the power source. You could take the power directly from the battery and say run pin 25 IAC A1 to the negative of the relay. I believe they are both the same diagrams, second is just a generic example. Purpose of the diode I believe is to protect megasquirt from seeing a huge voltage spike when the relay closes, I'm probably totally wrong on that though. Edited July 26, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 26, 2010 Author Share Posted July 26, 2010 (edited) I'm beginning to see your viewpoint. Are you saying that the transistor is really just switching on a ground? I know you mentioned this briefly before, but I've always been under the impression that a transistor either switches on or amplifies current. So looking at this diagram: http://i617.photobucket.com/albums/tt260/jacob80a/fancontroltransistorcircuit-2.jpg?t=1280075065 If I put my multimeter leads on Pin 27 and Pin 29 while Output 1 is off in megatune, I shouldn't see voltage, correct? Then, vice versa, if it is on, I should see 12v+, correct? Where I am confused is in my test: Output 1 off: 12.69v DC Output 1 on: 8.09v DC Why am I getting ANY voltage when the circuit is switched off? Perhaps I'm doing something wrong? I'm going to go back and put my leads on the emitter and collectors and do my continuity test. The only thing I am confused about is the voltages in my test. EDIT: I found this on physlink.com: "The collector is the larger electrical supply, and the emitter is the outlet for that supply. By sending varying levels of current from the base, the amount of current flowing through the gate from the collector may be regulated. In this way, a very small amount of current may be used to control a large amount of current, as in an amplifier." Is this a matter of electrical supply, or is this just a matter of completing a circuit, regardless of flow direction? Edited July 26, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 26, 2010 Share Posted July 26, 2010 (edited) Yeah no voltage when off, 12v on. So your getting constant ground, when it's on something is taking voltage. Check resistance between 29 and a ground. If it's showing continuity while off then something is wrong. When on it shouldn't be showing voltage if you take your leads and go to ground, or very little voltage. Edited July 26, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 26, 2010 Author Share Posted July 26, 2010 Yeah, thats what I'm thinking. Then again, I may have been poking the wrong pins. I'll let you know how my tests turn out! Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 27, 2010 Author Share Posted July 27, 2010 Ok, so here is what my test has concluded: ON: OFF: Why does my collector voltage go UP when I disable the output? Shouldn't the collector be at 0v/cut off ground to the relay?? Also, why am I only getting 8.2v when the output is on??? UGH, help! Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 27, 2010 Share Posted July 27, 2010 (edited) So it's looking like the transistor is working. Was the diode between the power source and 29? Maybe that is why your seeing voltage when you shouldn't. Actually I'm lost to why your seeing 12v when it's off, if there is no continuity between the collector and emitter then why would that be happening? Is this what your proto area looks like? Edited July 27, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 27, 2010 Author Share Posted July 27, 2010 Yes, that's what my proto area looks like, but for testing purposes, I only have my transistor installed right now as well as a lead fRom the processor going to the base of the transistor. Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 27, 2010 Share Posted July 27, 2010 So if you were to test from the none banded side of the diode, I'm wondering if you would see voltage while off. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 27, 2010 Author Share Posted July 27, 2010 Thats what I was thinking, I'll go ahead and wire that piece in place and let you know what my results are! Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 27, 2010 Author Share Posted July 27, 2010 Here ya go: Somehow, I LOST continuity when the output is on....ugh. I'm thinking I may have a bad transistor, but at this point, WHO KNOWS! Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 27, 2010 Share Posted July 27, 2010 (edited) The resistor would show 1k ohms resistance if you were to check it. I believe checking the diode you just check resistance and it should be open one way. Very high resistance in one direction and almost none the other. Maybe you need to run a wire from your output to a relay and power the other side. Then test it's operation. Check if 30 and 87 have continuity when on. I keep getting the feeling that going directly from a power source and and to the output isn't exactly the right way to test it's operation. If that doesn't work then you know for sure that something is wrong. From the looks of it you built the circuit exactly right. Edited July 27, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 27, 2010 Author Share Posted July 27, 2010 I haven't looked at your diagram above very losely, but I think I had a bad transistor. I just briefly had a chance to test my circuit with my new 2N2222 transistor from radioshack and I'm getting continuity/12v when on and no continuity/0v when off. Ahh, what a relief! I'll let you know what happens! Quote Link to comment Share on other sites More sharing options...
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