Cheap and cheerful DC motor soft start - Page 2 - Electronic Circuits Projects Diagrams Free

Sceadwian · 5th May 2009, 08:23 PM

I don't see a protection diode on the motor in the schematic you posted.

dieselhead · 5th May 2009, 08:54 PM

I did use one. It's a 1N5406. I must admit it's an old one which I haven't checked to make sure it works. It's soldered across the motor terminals

Sceadwian · 5th May 2009, 08:58 PM

Have you simulated that at all? You could just be burning out the Mosfet, I didn't look up the specs for power dissipation or anything on the fet you're using, if I have time later I'll pop it into LTSpice and see what it comes up with.

dieselhead · 5th May 2009, 09:06 PM

No i haven't simulated it

I can attach the datasheet for the MosFet

Its max power dissipation is 175W

dieselhead · 5th May 2009, 09:11 PM

Here is the datasheet

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5th May 2009, 08:23 PM	#16
Sceadwian	I don't see a protection diode on the motor in the schematic you posted. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

5th May 2009, 08:54 PM	#17
dieselhead	I did use one. It's a 1N5406. I must admit it's an old one which I haven't checked to make sure it works. It's soldered across the motor terminals

5th May 2009, 08:58 PM	#18
Sceadwian	Have you simulated that at all? You could just be burning out the Mosfet, I didn't look up the specs for power dissipation or anything on the fet you're using, if I have time later I'll pop it into LTSpice and see what it comes up with. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

5th May 2009, 09:06 PM	#19
dieselhead	No i haven't simulated it I can attach the datasheet for the MosFet Its max power dissipation is 175W