Electrojolt's Stable PWM Step By Step Assembling Instructions

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Ok, after installing those 2 switches, the Signal generation sections is completed and it can be tested.

If you noticed I'm leaving the C2 capacitor bank to the end so I can show you on how to select the caps, it will depend on the freq range you need...

To perform the test, I just place some caps in place with out soldering them. just make sure the legs are tight agains the holes so they connect.

Now the only thing left is the transistors and Mosfets.

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It is now transistor time...

I start with 3 NPN general purpose transistors like 2n2222 or 2n4401.

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Next 3 PNP General purpose transistors like 2n2907

so this pair of NPN and PNP will work to boost the current from the LM311 to drive the Mosfets.

I called them the drivers.

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Next I solder one more pnp transistor, same as the other 3.

this is used to invert gate the 3rd pwm, so when the second is on, the 3rd is off.

this can be used to trigger the EEC circuit.

Almost done, the only thing left is the mosfets and the optional back emf recovery diodes and cap.

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very neat, you etched it yourelf?

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Alan,

No, I didn't etched these my self, I have done etching in the past, the best method is using a UV lamp, transparant paper, and photo sensitive boards.

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To the last steps:

I solder the mosfets and power wires:

I'm using 2 output wires (orange) per output so it can handle more power.

If you planning to power something that needs more power you can use 2 Mosfets per channel.


3 555 timers
3 LM311 comparators
1 LM7808 8 volt regulator

2 100uf 35volt electrolitic cap
5 .1uf (104) seramic caps
3 1uf caps
3 10nf (103) caps
3 330pf caps (331)
3 2n2222 or 2n4401 NPN
4 2n2907 or 2n4403 PNP

3 or 6 FCPF11N60 Mosfets get some extra incase you kill some..
4 2.2kohm
13 1Kohm
3 10Kohm
3 100k or 200k or 500K Potenciometer
3 1K Potenciometer
3 10K potenciometer
8 on-on mini togle switches

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I forgot to post this 2.2k resistor, it is the link to Gate the 3rd PWM.