Custom H-Bridge (tha MOSFET mod)

Mostly dealing with electronics and pcbs and modifying them, all the things that make electrical-engineers tick and the rest of us cringe in fear.
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maximan
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Post by maximan »

ph2t, you should make a normal pcb that has all the stuff you want and the normal stuff for like turning i mean everything on one pcb
if you can't see my car now wait until i hit the boost botton
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Post by ph2t »

It's all about space max, and I don't have a hell of a lot. You need extra components to be able to turn on the FETs if you don't remove the original transistors from the RX PCB. Doing this and steering means the board would be bigger. More testing continues........

At the moment I wanna get:

1) Easy install, solder only 4 wires to the RX pcb.
2) High performance H-Bridge
3) Regulated 5V voltage source for LED headlights

Later as development continues:

4) Neutral brake circuit, for 3.8 motors and higher.
5) FET based steering.

ph2t.
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Post by ph2t »

Making progress pimps. Making the pcb is the current hurdle. I've been experimenting with using overlays printed on transparent overhead sheets.

Like this:

Image

This overlay is put on top of a uncut piece of copper sheet pcb that has been treated with a resistive coat. This is wedged between glass to ensure there is no space between the overlay and copper to ensure a sharp transfer.

This jig is then exposed under a UV lamp for about 30 minutes...

Image

This changes the chemical composition of the expose resist that makes all the pretty copper tracks appear during etching.

Got some more pics to upload but I've been having troubles getting this process right! :x

more to come.......

ph2t.
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noxorc
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Post by noxorc »

looks like your getting your process down.

can you layout a x586 motherboard for me? won't take ya long...

-nox


Good Job... Remember to mass produce this...so we all can buy one.
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Post by ph2t »

586 mobo hey? hah! :smile:

To busy making a custom games cartridge for my trash80....

ph2t.
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noxorc
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Post by noxorc »

ph2t wrote:586 mobo hey? hah! :smile:

To busy making a custom games cartridge for my trash80....

ph2t.

lol...trash 80.... ya gotta love'em...
they made me the wiz-kid at the mall years ago.
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Post by ph2t »

Testing stage by stage at the moment, trashed way to many prototypes getting this @#$%^ right!

A handy utility to come out of having a 5V source on the PCB to drive the FETs is that you can run headlights off it. The blue ones pictured below are bloody nuts and need a fair bit of voltage (3.6V) to turn on......

Image

:censored:

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Post by payaso »

This thread gave me a head ache...lol


silla :D
payaso...... :)

"Imagination is everything. It's the preview to lifes coming attractions" -Albert Einstein
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hogjowlz
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Post by hogjowlz »

so how long is a charge gona last with these leds runnin off the board?
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Post by ph2t »

With a 50sec charge at 1A gave me about 10 minutes with just the LEDs running. Measuring with a multimeter has shown that the current drain is about 30mA. This is just over 10% of the total drain the car pulls on the battery when in motion so it's not that bad.

Also, due to the increased efficiency of the FETs I've noticed a longer runtime generally because the motor is now getting a lot more current than before, the LEDs will offset this yes, but not by much.

Anyways real world results will tell once I've finished this beast. The LEDs are just a sideline to the main project of the FET pcb.

ph2t.
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Post by ph2t »

payaso wrote:This thread gave me a head ache...lol


silla :D
lol, it's given me brain spasms............ :wobble:

ph2t.
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noxorc
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Post by noxorc »

ph2t wrote:Testing stage by stage at the moment, trashed way to many prototypes getting this @#$%^ right!

A handy utility to come out of having a 5V source on the PCB to drive the FETs is that you can run headlights off it. The blue ones pictured below are bloody nuts and need a fair bit of voltage (3.6V) to turn on......

Image

:censored:

ph2t.
head ache? I think it looks like the starting project for the next StarWars character.

WireHead and PuddyButt.


-nox
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Post by ph2t »

:smile:

*expletive*
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hogjowlz
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Post by hogjowlz »

**falls off chair**
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bdebde
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Post by bdebde »

hogjowlz wrote:**falls off chair**
LOL.........**falls off chair** ;-)
Scotty, beam me up.
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