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Forum Index : Electronics : lm7808

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irishron40
Senior Member

Joined: 22/09/2014
Location: Ireland
Posts: 251

Posted: 07:36am 04 Jun 2015

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Hi I build a dutch style windmill.
have a 180 volt 4 amp treadmill motor fitted inside that drives the blades.

Iam able to operate this motor on 6 volts as I dont want it to spin to fast.

now my problem is this.

it will work on my bench power supply at 6 volts

it also works on a 6.3 volt 600 miliamp phone charger.

but it refuses to work on a lm7808 run from car battery.

battery is fully charged.

I checked amps draw , and at 8 volt it draws 0.49 amps

just confused why it wont work on the lm7808.

the only thing i can think of is that by startup it might draw a bit more and that lm7808 isnt able for that.

maybe capacitors shoul;d sort it?

just wonder what size caps on the output

thx

ron
Edited by irishron40 2015-06-05

irishron40
Senior Member

Joined: 22/09/2014
Location: Ireland
Posts: 251

Posted: 11:12am 04 Jun 2015

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ok , I got it working on a 7805 transistor

on the output of the transistor I have 3 16v 2200uf caps and a 1n4007 diode as the treadmill motor is also a generator.

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