P259 amplifier

[Mads Lund]

Hi all

After trying out the VEMS ETC expansion board, and found out that it is a P channel FET driver (+12V switching), the p259, ignition and injector output's are N channel (negative switching). So using the ETC board require a different wireing to all the loads.

So I have made my own P259 amplifier, with N channel FETs IRF640N like in the injector drivers, with 5 channels to amplify the 5 outputs from the EC36 connector (not amplifing the tacho, but the remaining 5)

Further did I include a 12V to 5V usb DC-DC converter to power the Airconsole Wifi->RS232 adaptor. And the airconsole is actually a great vems device, enabling both bluetooth and wifi connection. The wifi runs stable at 12-14 Hz in vemstune. And no cables needed :-) power on the car and sit at the workbench with a cup of coffee.

I have 30 spare pcb's if you are interested.

The amplifier simply need 12V+, GND the 5 wires from the EC36 P259 outputs, and have 5 Amplified outputs. I'll make a schematic if you need. installed in a small Vems'like casing, with a EC18 connector.

And now i have full protection of the p259, with 5 aditional 10A outputs. And the board is made so it can be used for high side FET's as well (12V switching), so can be quite usefull for other installs where you want to use the car's existing relays for fan, pump etc. if the are 12V switched. The board have schottky diodes that will protect the FET from relay transients. So no need for protection diodes on the relays any more, also making installs more easy.









 

 

[Mads Lund]

An update on components on the board:
The blue pull-up resistors are 10kOhm
The brown current limmiting resistors are 33 Ohm
FETS are IRF640N
Protection diodes are 1N5822
Zener reverse voltage add-on 1N5355 or similar 18V

And one small design topic, the track that connects the 12V+ to the 5 protection diodes, need to be cut, and a zener 18V diode 1N5355B must be inserted, in order to avoid reverse current from eg. powered relay to the 12V. In some applications will it be irellevant, but just to be sure.

[Kamuto]

would be nice to make one with dbw

[Mads Lund]

Schematic

[TC-Tuned]

i like this, well done, how much is a bare pcb?

[wersch]

I like the concept of this driver:
https://www.diyautotune.com/product/hsd-4-high-side-driver-4-channels/

ok this is a highside driver but its very compact, perfect for complementary installs.
Is there anything similar to buy here in europe?

[Mads Lund]

The VEMS ETC board works as a high side driver, including 2 H bridge drivers.
https://shop.vems.hu/catalog/bridgeoutputdriver-p-185.html?osCsid=a76908d09c1e7f1a85e3970986371328

[wersch]

Yes i have vems ETC driver on my bench here right in front of me, but its rather big if you only need it to drive some extra outputs.