H-Bridge for Wally the Wall bot

[Conscripted]

Good morning all.

I recently purchased the book "Arduino Robotics".  Chapter 5 has a bot called "Wally the Wall-bot" that I'm interested in building. I was hoping some one here has already built the h-bridge. I would hate to purchase the parts, put it together and then spend a bunch of time debugging the circuit if it's a poor design.

I found a digital version of the schematic HERE. The page with the schematic says "175"
The circuit uses

• (4) 2n7000 - logic level N channel mosfet
• (4) FQP50N06L - N channel power mosfet
• (4) FQP4706 - P channel power mosfet
• (2) TC4427 - MOSFET driver
• (4) 10k resistor
• (4) 150-ohm resistor

The H-Bridge is stated to work at 18VDC, 5A continuous, and PWM at 32KHz.

Does anyone have any experience with this circuit?

Thanks.

Conscripted

[waltr]

That H-bridge circuit is isn't too bad.
The major issue I have with it that both the low and high MOSFETs could be turned on at the same time. I call this the "Smoke' condition since it produces a short circuit.

[Soeren]

Hi,

There's the possble current shoot-through as waltr mentioned and it strikes me as very odd and inconsequent using a MOSFET driver for just the low side and discretes (of a lower current handling capability) for the high side - I don't believe it's made by a pro.
Apart from that, it should work if controlled correctly

[Conscripted]

Thank you both for your input. I was pricing the parts out and it looks like it will cost me about $25 plus shipping. Do you know of a better design that is comperable in price and specs?

Conscripted

[waltr]

1- look up Soeren's posts. He his posted schematics of H-bridges in the past.
2- With all of the integrated H-bridge chip available I haven't build a discrete H-bridge in many years.  Search through threads here on H-bridges for some suggestions.
Also, google will help find others.