hi,
If you look at the image in my post #15, you will see that there are two LS123 monostables in that plastic body.
Try your circuit using the second LS123 part.
What voltage do you measure on pin 13 of the LS123.???
Based on the sheet I did find about the LS123 (see attached), ok I see what you are talking about on page 2, but then the output should but pin 5 right? not pin 13.. which would be out of the circuit right?
I'm going to make the test now.
Based on the sheet I did find about the LS123 (see attached), ok I see what you are talking about on page 2, but then the output should but pin 5 right? not pin 13.. which would be out of the circuit right?
I'm going to make the test now.
hi,
Dont forget to move the timing resistor/cap etc over to the new pins, pin5 is the 'new' output...DONT connect the 1k and LED, measure it first when you have finished changing it.
You didnt say what voltage you had on pin 4 the 'old' /Q...?
hi,
The reason for asking you to measure the pin4 voltage on the original circuit is because its the complementary output, I was interested to check that it was at close to +5v.
If you are using the 'new' half of the LS123 ic, then the 1K and series LED have to goto pin 5.
The RED led cannot cause the problem IF you have a 1K series resistor.