No limit ESC schematics. Help me please.

[Gigillo]

Hi,
i'm Luigi and i'm writing from Italy.
From 2002 i'm interested in RC model Car.
I've buy a new car chassis (TA04 pro tuned) to make some contest and a new 10 turn motor.
Actually i've an ESC that have 17 turn limit and i couldn't mount the new motor.
I like electronics and i'm a little expert in this matter so i ask if someone have a microcontrolled (prefer PIC 16f84) based no limit turn ESC schematics without reverse.
Thank You in advance.

[alexcmag]

Options:

- You can double the MosFETs on your current ESC
- You can make this ESC: http://www.designsoft.com.au/ahome/rc/PIC-ESC/ , use a Optocoupler (4N25) to drive FETs, and use 4 IRF3205 FETs, in example, each one can handle 15A without overheating, 4 in paralell can handle over 100A without any trouble and without risk of interference.

[xtal]

try this ....
http://homepages.paradise.net.nz/bhabbott/electronics.html

[Gigillo]

Thank You for schematics suggest, but are they suitable for a high current motor for rc car models?
Some car ESC give much more current to drive motor.
Thanks.

[alexcmag]

Gigillo,

What limits the current are wires, FETs and schotky diodes.

Use thicker wires, better FETs in paralell and bigger diodes and you can start a truck's engine with the ESC.

[Bruce Abbott]

A 'no limit' ESC needs to handle at least 50A continuous and 200A peak. You can make one based on a lower current design. You just need enough paralleled MOSFETs to meet the current specs, gate driver circuitry powerful enough to turn them on/off quickly, and Schottky diode(s) rated for at least 25A continuous. Of course, the wiring must also be fat enough to handle these high currents without frying!

For example, you could use 3 x IRL3803 MOSFET and 2 x PBYR1645 Schottky diode. This combination should handle 220A peak current, with a voltage drop of about 0.1V at 50A. Power loss is about 1.7W per FET at 50A, so a small heatsink would be required. The Diodes will also need heatsinking, as they may dissipate a few watts each at part throttle (but don't worry if they get hot, they are more efficient at high temperature!).

[Gigillo]

Hi,
thank you Bruce Abbott for your suggests on NO LIMIT power design of the ESC.
IRF3803 is ok!
Please have you a 16F84 based schematics that i could modify the power stage to use it how a NO LIMIT ESC?