3 Battery Generating System

[Turion]

One other thing I would suggest is putting an on/off switch between your stamp and its power supply. If things go South you want to be able to kill the power quick.

The STAMP runs off of a 9 volt battery, or you can hook it to an isolated 12 volt battery as Matt has discussed. If you use the 9 volt you STLL have to have a 12 volt power supply to run your board. If you purchase a snap on battery connector that will snap on where the 9 volt battery was supposed to go, REMEMBER that the RED wire coming off that snap on connector goes to GROUND and the BLACK wire goes to POWER. That connector is made for snapping onto a battery, not IN PLACE of a battery. Look at it carefully and you will see what I mean.

[ehsanco1062]

I know all about blowing up boards! LOL One down, two to go!! have been running tests for the last hour or so since Matt helped me to correct a number of errors plus the connections on the board that needed a wire soldered on to complete them. My issues with the board were NOT the same as what you experienced. Or at least I THINK the issues were different. Where the resister connects to the 3120 there was no trace, and since it is such a small gap, I bent the end of the resister over and soldered it to the 3120 to make sure there was a complete circuit, which eliminated the NEED for a trace there. They are so close you could almost solder them together if you are careful (if you have already cut them off) My terminals also did not want to fit into the holes, but I solved that problem by laying the board on a piece of soft wood, placing a block of wood on the terminal, and tapping on it gently until it went in. It was a tight fit, but it went. Once they were in there was a connection to the resister, I checked with a meter. SO I didn't have any soldering to do there. I would advise you to check the back of your board to see if all the resisters connect to the 3120's. There was a trace on the first one, but not the rest.

Dave

Sorry about that Dave , doing or learning things are always not free .and blowing up things that’s what I do every day and that’s how learn aren’t we?
And thank you for the information.

Ehsan

[ehsanco1062]

Hi Matt

Thank you for the codes
I will try to read your explanation more to understand what is going on in this setup hope I will not blow up things this time.
I did the jumper you mentioned and did finished winding my transformer and by the way it’s not 250w its 75 w but any way I wind 8 wires #23AWG 12m but I did one mistake in my order ,I order for 3 fast diodes instead of 4 and I have more than 40 diodes of the same diodes I use in your tesla switch they are Digi-Key - FFPF15UP20STTU-ND each one is 200v 15A can I used 4 of them in parallel instead of one diode of these (RURG5060-ND)?
When I check these diodes ( FFPF15UP20STTU-ND ) in Digi-Key now they are using the same diodes with three pins not two pins the one I have with the same part number.

Ehsan

[Matthew Jones]

Ya those diodes should be a problem.

If you need any more explanation let me know.

Matt

[ehsanco1062]

Hi Matt

I orderd for one ultra fast diode but this one is 600v 70A not 50A llike the other three wouldn't that be a problem or it is ok because if I will by the the same diode from Digi key it will coast me 40$ so I bought this one for 15$ less than half price.

Ehsan

[Matthew Jones]

Ya thats fine. You could use those diodes you listed earlier. Your not going to exceed 15 amp

But either way that one will work.

Matt

[rosehillworks]

c1 d2

Matthew
Please help me here I do not understand how C1 can discharge through F3 when
D2 is blocking it's + path to P1. Would it not work like this instead?

PosFix.jpg

[Turion]

Either my problem wasn't that I blew the series fet, or I just blew another one instantly, because I replaced it and am still having the same problem. I may not get back to this until Monday morning, because I have a full day scheduled tomorrow. Will check every connection on the thing to make sure all is well and then try running it again, and THEN begin the process of looking for voltage at various places in the circuit to see what is going on and where the failure point is.

It was running great until I put in the new program, but I didn't even run it before deciding to run the test program again and get exact voltage measurements, so I don't know what I changed that could have messed it up, unless I entered the program incorrectly

Dave

[Matthew Jones]

Matthew
Please help me here I do not understand how C1 can discharge through F3 when
D2 is blocking it's + path to P1. Would it not work like this instead?

[ATTACH]11512[/ATTACH]

F3 discharges C1. D2 is in place to straighten the AC out. F2 Discharges C2.

Follow me?

Matt

[Matthew Jones]

Either my problem wasn't that I blew the series fett, or I just blew another one instantly, because I replaced it and am still having the same problem. I may not get back to this until Monday morning, because I have a full day scheduled tomorrow. Will check every connection on the thing to make sure all is well and then try running it again, and THEN begin the process of looking for voltage at various places in the circuit to see what is going on and where the failure point is.

It was running great until I put in the new program, but I didn't even run it before deciding to run the test program again and get exact voltage measurements, so I don't know what I changed that could have messed it up, unless I entered the program incorrectly

Dave

Unhook L1 and L4. You most likely blew another fet instantly. You have 100 volt fets and you might have 350 volt spikes coming off of those 2 windings.

I gotta fix for it I think but I trying to get mine setup so I can see first hand.

Also test the fets with light bulb and regular circuit and see of they are open. I'll draw something and post it for testing fets.

Matt

[Turion]

Matt,
There is an unused DC to DC converter on our boards. Couldn't we hook direct to that from say pin 5 on the Stamp and run a program to light a bulb using the fets? That would give us a reasonable test and all we would have to do is disconnect the four wires from an existing fet and hook up some new ones.

Dave

[Matthew Jones]

Ya.

Just come out of the hot on the battery go through a bulb. The from the bulb to the Drain of the Fet. Then go from the source to the ground of the batt.

Now hook up the driver board and run a program like this.

' {$STAMP BS2}
' {$PBASIC 2.5}

DO
HIGH 5
PAUSE 1000
LOW 5
PAUSE 200
LOOP

That will run a bulb and make it blink once a second.

Then you'll know if the FET is ok.

If you go to hook it up and the bulb comes on without the code running your fet is bad.


Do not hook up any more Fets David just leave it alone I'll have a solution by tonight.

Matt

[Turion]

I can't help but think my problem is other than the high voltage spikes. I never saw more than about 48 volts in the cap and I ran the test program about five times before the problem started, charging and discharging the caps. If the fet could stand up to 100 volt pulses and the cap holds more than 100 volts, if the fet was getting hit with voltage over 100 volts wouldn't you expect to see at least 100 volt in the caps??

I'll see if I can't get down there this morning while the wife is still asleep and at least test the fets and see if that was the problem before we head out for the day. It's only 5:30 so I should have a few minutes.

Dave

[Turion]

I was wrong. All three fetts are dead It might still be that somehow I have something wired wrong. I will go back through all the wiring, and I definitely won't hook up anymore fets. None of the lights came on when I made the connections, but none of them came on when I ran the program either. So to be SURE, I need to measure voltage coming out of my DC to DC converters and make sure 12 in and 15 out. I will do that right now and post in a few minutes. Maybe THEY are blown instead of the fetts. That's what blew on my first board...all four of them, even though one wasn't being used.

OK...The DC to DC converters are A-OK, so it is either the fetts or my wiring. I will eliminate one possibility sometime today or first thing in the morning for sure. I have checked the wiring a couple times already but third time is the charm.

And maybe I need to be looking st some different fets?

[Matthew Jones]

I can't help but think my problem is other than the high voltage spikes. I never saw more than about 48 volts in the cap and I ran the test program about five times before the problem started, charging and discharging the caps. If the fet could stand up to 100 volt pulses and the cap holds more than 100 volts, if the fet was getting hit with voltage over 100 volts wouldn't you expect to see at least 100 volt in the caps??

I'll see if I can't get down there this morning while the wife is still asleep and at least test the fets and see if that was the problem before we head out for the day. It's only 5:30 so I should have a few minutes.

Dave

No the spikes are 350 - 500 volt more than likely. So the fet takes the abuse a few times then gives up. More than likely it will decide not to work after you shut it down as opposed to while its running.

Matt