Assembling
Instructions
Steps
- Solder IC sockets for ADC, DAC, opamps and U?? driving the
digital output.
- Solder all other components directly to the PCB. (temperature 300
degree centigrade, soldering ion tip grounded preferably)
- Check +5V output of 7805, +12V output, -12V output of 7912 with
multimeter
- Adjust the potentiometer to make the LM317 output to 5V.
- If you have a CRO put it in AC mode and check the amount of noise
in supply lines.
- Connect the 25 pin FRC connector to the PC. Make sure that pin
numbers are matching otherwise you will spoil your PC. If you are in
doubt connect the cable to the PC (other end free) and write a ONE to
data register of the printer port (address 378hex). Pin number two of
the connector should show around 4V. Now write a ZERO to the address
and the voltage should goto nearly zero. That PIN should match with the
pin number two of the FRC connector on the PCB.
- At this stage you can run the test the Digital Input/Output
features. Use the test programs provided for that purpose.
- Now insert all the components like ADC, DAC etc.
- Set a known voltage to the DAC and measure it with a meter. Use
the test program for setting the voltage.
- Write a positive voltage to the DAC and loop it back to the ADC
input. Read the ADC and compare
- Check the 555 and 8038 oscillator outputs using a CRO if you have
one.
- Set the DAC to 100 mV and test all the Amplifiers using it.
Adjust the offset to
- Connect all the sockets to the Front Panel and solder the ribbon
cable connections. Here is the Connector Details.
- Fix the PCB inside the box and connect the ribbon cable to the
FRC conenctors. PCB need to be kept nearly vertical during this due to
short cables. Do not make the ribbon cables very long.
- Ground the 10X and 200X Amplifier inputs and adjust the offset to
get 0V output. Give 20 mV at 200X amplifier input.
- Close the box and run the test programs.