The 7662 is a voltage inverter that takes a positive voltage and creates a negative voltage of equal magnitude. In this step, the IC will be installed, power applied, and the output checked.
|Install the 7662 8-pin DIP IC at U15. The notch or pin one is oriented towards the top of the board. Be careful not to bend any pins under.|
With the multimeter ground connected to the anode of D4 (same as before), apply power and
check the voltage on ‘D’ at JMP2 (next to the single RJ11 connector on the RH
side of the board). It should read approximately -12 VDC. Note: If the board has been
strapped for the RM60/RM70 background radiation monitor, it will read -9 VDC.
|Disconnect the power source.|
If you do not read the correct voltage, disconnect immediately. Find and correct the problem before continuing.
Remaining IC Installation
Just a reminder to check for pins that might be bent under the IC. Carefully check alignment before pushing the IC into the socket.
|MAX232CPE, the RS232 converter, at U10. The notch (or pin one) is oriented towards the bottom of the board.|
|TL084, the instrumentation amp for the pressure transducer, at U7. The notch (or pin one) is oriented towards the top of the board.|
|4N28 Opto-Isolator at U1. The notch (or pin one) is oriented towards the bottom of the board.|
|4N28 Opto-Isolator at U3. The notch (or pin one) is oriented towards the bottom of the board.|