Transistor Beta and Vce Tester

This was a Beta Hfe and Vce Measuring Instrument used in Incoming Inspection of Power Transistors made by me 16 years back.

Transistor Beta Tester

Custom Built Test Instruments

I designed and built many custom “engineered” Test Instruments. They were not prefect, as only one or two were fabricated. That means it will be costly to produce such instruments. It is just like tooling, you have to make some numbers to recover costs, or price it very high to compensate for the wastages and iterations.

  • Display ICL7107 – Temperature controller
    This is the Display Circuit and PCB part of of section Temperature Control. The above circuit is powered by +5 and -5 from a LM7805 [...]
  • Voltage Attenuator Amp – DMM Project
    LF356 opamp FET input is in a inverting amplifier configuration here. R4 + R5 make up Ri each 1/4 W MFR withstands 250V so both [...]
  • DC-DC SSR Solid State RelayDC-DC SSR Solid State Relay
    This is a DC Input DC Output SSR Solid State Relay. It was made for Printing or Photo Processing Equipment. It has an optical isolation [...]
  • Running Lights with CD4017
    The 555 Astable generates a clock for this circuit, an oscillator giving a square wave output at pin 3 which is counted by 4017 to [...]
  • Current Source for Resistance Measurement
    Here is a current source you can build for resistance measurement. When the current is held constant, you know as per Ohm’s Law the Voltage [...]
  • 555 watchdog for uC and uP systems
    When the microcontroller hangs due to a spike, EMI or RFI etc. the 7555 will reset the uC, if proper power supply design is done [...]
  • Proportional Module for Process Controller
    When you need a proportional control output, either 4-20mA or Time Proportional On-Off, This module is used. It does a slow PWM control, the cycle [...]
  • 0-1V to 4-20 mA Converter
    This two opamp circuit converts analog voltage signals to current (sink) signals in a proportional manner. Current signals are more immune to noise and cross [...]
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Product Design - Industrial Automation and Instrumentation. -