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Can you show the external circuit/connections to CN1/2/3 please.
Oil well ignition module
- Thread starter MarkySparky42
- Start date
Sure thing
give me a about an hour and when I’m at work I’ll sketch something.
First connector is for the trigger coil
the middle connector is for HV in
The right most connector is for coil out
here is a picture of the voltage from the trigger coil when the trigger magnet was at 500 RPM
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As I thought, your circuit is wrong. Here is my recreation of it in an easier to read form and its obvious why it fails. When you trigger the SCR all it is doing is shorting the supply. Once the SCR triggers there's nothing to turn it off until the output of the 350v supply drops below approx 10mA or it destroys itself...
The lower version limits the current with a 500 - 1kohm resistor. It works, but the resistor dissipates nearly 100W! So not practical...
Solution in next post...
Ok that makes sense.
I remember or at least thinking I saw, one spark from the plug before it died.
If it helps at all… the original Cornell-Dublier cap from the old module was 3.9 uF 600V rated.
The difficulty is the 350v supply. Current limiting its input works for now, but its still being stressed and reliability is suspect. Current limiting its output is not practical. Turning its output off by controlling its input is not likely to be practical due to its likely start-up time. Therefore two options remain (tho' open to other suggestions): (a) control its output with a 'switch' or (b) replace it with an alternate supply with more useful output characteristics. I'm currently (excuse pun) looking at option (a) tho' switching 350v on & off isn't easy.
What battery volts are available? 12v, negative ground?
It’s run off of a 12vDC truck battery that is charged by a solar panel.
… so if I understand you, we have issue of the gate not closing.
here are two circuits I found online where people were making CDIs for mopeds in India.
I bread-boarded all of these and they make a nice spark but now that I think back, I was using the same 120VAC-12vDC plug in power supply.
here are two circuits I found online where people were making CDIs for mopeds in India.
I bread-boarded all of these and they make a nice spark but now that I think back, I was using the same 120VAC-12vDC plug in power supply.
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And they all have the same issue - they are magneto powered so chopped DC input which turns itself off. except #2 which is not CDI just a transistor switch.
Sigh… I see that now… darn it.
That explains why the output cap as getting hot… how about a solid stat relay?
That explains why the output cap as getting hot… how about a solid stat relay?
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SS relay unlikely to handle 300v DC at 5A; a quick look suggests very few such, and very expensive...
Hello,
There is a 50 A 650 V DC SS relays here for about 600 Euro:
https://nl.rs-online.com/web/p/solid-state-relays/7026804
Bertus
There is a 50 A 650 V DC SS relays here for about 600 Euro:
https://nl.rs-online.com/web/p/solid-state-relays/7026804
Bertus
Ok. There has to be a different solution.
Please - anyone.
Please - anyone.
I mean besides building an inverter and plugging a wall wart into it. Which works…
So I’ve been thinking about this and my trigger voltage generated by the coil in the magnet is of a sufficient magnitude to trigger my gate on my SCR. And my triggering waveform is sinusoidal (see picture). Doesn’t the negative part of this wave shut off my SCR?
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so this is apparently a dc only CDI circuit.
