Maker Pro
Maker Pro

PWM Circuit

Edwin Fitzpatrick

Dec 26, 2012
23
Joined
Dec 26, 2012
Messages
23
I built a PWM motor control circuit using a TL494CN chip, Workes good ,But can not go to 100% on . How do I get this chip to go from off to full on. IT will go full off but will only go to 95% on at full pot.The circuit is from Electronica,60 A PWM motor controller Article.
Tnx,Fitz
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
The TL494 has bipolar switching elements. Depending on your topology, there may be a voltage drop that you can't easily avoid.

Post a link to the schematic.

A simple solution may be to start with a slightly higher input voltage to compensate for the losses across the switching elements.

edit: Is it this?
 

Edwin Fitzpatrick

Dec 26, 2012
23
Joined
Dec 26, 2012
Messages
23
Hi Steve,
The Web site is in my message ,ELECTRONICA,60 A PWM MOTIOR CONTROLLER.This is a circuit for a electric scooter,What I am building is a 36 volt electric cart.I need 100% on when I push the throttle to the floor.IT uses 10 IRFZ48 Hex ferts in Parallel.The article says that the circuit will go from 0 to 100% pwm.I tried all modification to the circuit and the max I can get is 95 %. IT goes to 0 % ok. This may be the best the TL494CN will do.Why would anyone want to build a motor controler that would not go to 100% on ?????
Fitz
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
The TL494 has bipolar switching elements. Depending on your topology, there may be a voltage drop that you can't easily avoid.

Post a link to the schematic.

A simple solution may be to start with a slightly higher input voltage to compensate for the losses across the switching elements.

Is it this?

edit: Not that I want to repeat myself, but you have not addressed any of these vital issues. And there is no link in either of your posts.
 
Top