RESONANCE EFFECTS FOR EVERYONE TO SHARE

[TinselKoala]

I agree about the TVS potentially killing the "interesting" effects.
I usually put an additional fast diode across the source and drain of each mosfet, even though they have internal diodes, to channel the flyback pulse away from the transistor. But I feel the same way about these as I do about the TVS.
The driver chips are supposed to control the timing of the MOSFETS so that shoot-thru (both on) and no-current (both off) times are minimized. Other controller chips like the Intersil HIP 4081A have the capability to fine-tune these parameters.
There's some good stuff about power dissipation in MOSFET h-bridges in the Intersil application note:
http://www.intersil.com/data/an/an9405.pdf

[najman100]

@ all
Groundloop
TinselKoala
Gotoluc
Wattsup
send me via pm your addresses and i have room for one more Groudloop you decide whom i will ship if everything is ok at the end of this week .
i decided to trim a litill bit of the PCB so we can mount the transistors on a heat sink.
i just bought a 1/32 inch epoxy double sided presensitized copper clad board .

here is a pic attached

Najman100

[TinselKoala]

Lookin good, Najman!!

Yes, builders should definitely use heat sinks for the transistors. If you use separate ones like I did, and don't let any other circuitry touch them, you can dispense with the insulating rubber or mica gasket and just mount directly to the heat sink. If you use a single sink for all the transistors they must be insulated electrically from the sink.
I realize it's a little late for design changes, but I find the addition of the LEDs on the mosfet outputs is a great help in troubleshooting and in demonstrating to others just what the H-Bridge is doing. These LEDs should be capable of being switched out of the circuit once things are running like you like.

Also, for those builders who might be constructing the "old" version using the IR 2103 (or 2104) drivers: I find that it is best to have the logic power ON and the clock signal supplied to the 4013, BEFORE applying main power to the bridge. If you put power into the bridge too soon, the mosfets aren't switching and may overload and pop.
Do you really need to ask how I found this out??

[najman100]

Lookin good, Najman!!

Yes, builders should definitely use heat sinks for the transistors. If you use separate ones like I did, and don't let any other circuitry touch them, you can dispense with the insulating rubber or mica gasket and just mount directly to the heat sink. If you use a single sink for all the transistors they must be insulated electrically from the sink.
I realize it's a little late for design changes, but I find the addition of the LEDs on the mosfet outputs is a great help in troubleshooting and in demonstrating to others just what the H-Bridge is doing. These LEDs should be capable of being switched out of the circuit once things are running like you like.

Also, for those builders who might be constructing the "old" version using the IR 2103 (or 2104) drivers: I find that it is best to have the logic power ON and the clock signal supplied to the 4013, BEFORE applying main power to the bridge. If you put power into the bridge too soon, the mosfets aren't switching and may overload and pop.
Do you really need to ask how I found this out??




i smell something burning

[Groundloop]

@Najman100,

Looks great. :-)

But why trim the PCB? I designed the PCB so that you can mount the transistors
two ways. One, standing up and mounted to a heat sink. Or, lying down bolted to a L shape
alu. profile. Then the Alu. profile can be bolted to a bigger heat sink.

I some cases the user want to use a low load and then the PCB itself will be the heat sink.
That is way I have copper under the transistors. Same goes for the 7805 regulator. The PCB
will be the heat sink.

@TinselKoala,

You can always add a couple of wires to get your LED display. I did not put in anything extra
because I want the circuit to use as little power as possible.

Groundloop.