Years
ago i bought one of the cheap capacitance meters with built in LCD
display. It promptly died on me. I cannot remember for sure but i may
have been testing an electrolytic with a charge. Anyway, for hobby
work, i did not want to buy another meter of this type and really did
not want to spend mega bux on a higher quality unit that i still could
not likely repair myself.
After looking in the ARRL handbook, i came across a fairly simple circuit for both capacitance and inductance. And the best thing is i can, in all likelihood, fix the unit should it fail !
You can find the schematic to this unit in many of the ARRL handbooks and i suspect on the ARRL website although i have not looked. These utilize the 74hc132 chip.
Picture below; Main board houses the 2 circuits. The small circuit board on the back is for the common IC power regulator. The black box next to this is a wall wart type power adapter. I mounted inside the housing for a neater araingement. Construction is through hole perf board and point to point wiring. The box is an old rusty electrical housing that I sanded down and painted.
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After looking in the ARRL handbook, i came across a fairly simple circuit for both capacitance and inductance. And the best thing is i can, in all likelihood, fix the unit should it fail !
You can find the schematic to this unit in many of the ARRL handbooks and i suspect on the ARRL website although i have not looked. These utilize the 74hc132 chip.
Picture below; Main board houses the 2 circuits. The small circuit board on the back is for the common IC power regulator. The black box next to this is a wall wart type power adapter. I mounted inside the housing for a neater araingement. Construction is through hole perf board and point to point wiring. The box is an old rusty electrical housing that I sanded down and painted.
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