EHHA Rev A Schematics


Mosfet One Channel Schematic

The EHHA Rev A Mosfet version schematic.

EHHA Rev A MOSFET One Channel

 

BJT One Channel Schematic

The EHHA Rev A BJT version schematic.

EHHA Rev A BJT Single Channel

 

Rail Power Supply

The on board rail supply is a very conventional split supply using adjustable linear regulators.

EHHA Rev A Rails PS

EHHA Rev A Split Rail Supply

 

Heater Supply

The EHHA Rev A board provides two heater supplies depending on whether you are using a 6.3-7V transformer or a 9V transformer. With the stock components the supply is adjust in approximately a 1V range around 6.3VDC.

6.3-7V Transformer

Use 1N5822 Schottky rectifiers for this power supply.

EHHA Rev A Heater PS 1

Heater Supply for 6.3V Transformer

9V Transformer

Use UF4004 rectifiers for this power supply.

EHHA Rev A Heater PS 2

Heater Supply for 9V Transformer