Schematic supply connetion, 5V or 9V?

J

Johnson777717

New Member

• Aug 18, 2004

• #1

Good day folks!

Would you mind helping me to determine the unknown connection in this circuit? I believe this is a 9V connection, but I'm not sure, it could be a 5V connection?

Please see the arrow pointing upwards at the top-middle of the schematic between C6 & R6. Thank you for your help!

 

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R

red4925

New Member

• Aug 18, 2004

• #2

Check and see what kind of supply voltage those NAND gates require.

 

Roff

Well-Known Member

• Aug 18, 2004

• #3

74HC logic definitely requires 5 volts, and will not work (permanently) on 9v.

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Aug 18, 2004

• #4

It looks like the Weeder frequency counter?, it works off 9V but has a 5V regulator on board for feeding the PIC, LCD and TTL. The front end FET's are fed from the 9V supply though!.

 

J

Johnson777717

New Member

• Aug 18, 2004

• #5

It looks like the Weeder frequency counter?

Click to expand...

BINGO! Mr. Goodwin gets the cookie

74HC logic definitely requires 5 volts, and will not work (permanently) on 9v.

Click to expand...

Yeah, I got to looking at the schematic during my lunch break at work and came to that realization! Doh!

Thanks for your help folks, sorry to waste your time.