Back in June I was asking about a flyback diode to go onto a 12 volt blower. I think that subject has been covered. So I've built this circuit below, you may have seen it. Here's what it IS doing and what it is NOT doing:
First, it consists of a dimmer control out of a 1989 Toyota car - the dash board dimmer lights. First question you may have is "Does the dimmer work?". Answer - Yes. It's PWM and it is PWMing. Checked it with the scope. Its output varies between 5% and 95% with full on and full off at either end of the pot. So it can switch to full on or full off or somewhere in-between the 5% and 95%. However, my IGBT doesn't seem to be doing anything. Is my thinking wrong? Applying power to the gate via the Sink doesn't turn the test lamp on. Have I got the wrong IGBT? Or just wired wrong?
I've cut the 1KΩ resistor out. No change. I've jumped the resistor (what was V+) to Neg. No change. The IGBT is IRG4PSH71K and I'm not good with data sheets, but it looks like it takes about 15 volts to turn on. Yes? No? I've set my supply to 15 volts but it still doesn't do anything. Tested the light bulb with the PS set to 15.9 volts. Upon connecting the 12 volt tail-lamp the lamp lit but the voltage dropped to 6.2 volts. When I connect the blower (after verifying the circuit works) it will be powered from a 12 volt car battery.
I'm at a loss. Stuck.
Note to moderators; if this is in the wrong category - sorry. I only know I need help.
First, it consists of a dimmer control out of a 1989 Toyota car - the dash board dimmer lights. First question you may have is "Does the dimmer work?". Answer - Yes. It's PWM and it is PWMing. Checked it with the scope. Its output varies between 5% and 95% with full on and full off at either end of the pot. So it can switch to full on or full off or somewhere in-between the 5% and 95%. However, my IGBT doesn't seem to be doing anything. Is my thinking wrong? Applying power to the gate via the Sink doesn't turn the test lamp on. Have I got the wrong IGBT? Or just wired wrong?
I've cut the 1KΩ resistor out. No change. I've jumped the resistor (what was V+) to Neg. No change. The IGBT is IRG4PSH71K and I'm not good with data sheets, but it looks like it takes about 15 volts to turn on. Yes? No? I've set my supply to 15 volts but it still doesn't do anything. Tested the light bulb with the PS set to 15.9 volts. Upon connecting the 12 volt tail-lamp the lamp lit but the voltage dropped to 6.2 volts. When I connect the blower (after verifying the circuit works) it will be powered from a 12 volt car battery.
I'm at a loss. Stuck.
Note to moderators; if this is in the wrong category - sorry. I only know I need help.
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