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Lab Benchtop Test Instruments

Regulated Power Supply 30V 5A


This is a Regulated 0-30 V DC Power Supply manufactured by me in small numbers, 0-30V 5A and 5V -5A. It had a Switching Preregulator. This keeps the Vce across Transistor Bank at the Back of Instrument, at the lowest possible level, in order to keep them Cool. When Vce and Ic both are more in a Power transistor it will get heated more, then the efficiency of power supply is low.

The Output had both Constant Current Control and Constant Voltage Control. The CC control is also a Short circuit protection. The Output was protected from outside voltages damaging output circuits even when equipment is switched off. The back panel is a finned anodized black aluminum heat sink with many transistors.

The catalog that was made is here - Regulated Power Supply 30V 5A

I looked for the circuits to scan them, i could not find it. I made-n-sold quite a few of them years ago. All of them work well even today as i over-rated most components. The cabinet was Steel for EMI-RFI Immunity, it was painted with Stipple Matt Powder Coating, the Cabinet maker had just learnt to give such a finish to his boxes.

Regulated Power Supply 30V
                        5A

SMPS have now replaced Regulated Power Supplies that use a Low Frequency Step Down Transformer. Switching Supplies are light and small, very efficient too (power conversion).

High Efficiency Step Down Isolated Supply - This is a SMPS which is used to Power Equipment.

Tera Ohm Meter and Insulation Tester


This is a 20 Tera Ohm Insulation Tester I made around 20 Years Back. It had even Polarization Index for Transformer Insulation. It generated 1000V DC Regulated Voltage and the pA leakage Current was Measured. See more here Insulation tester or Tera ohm meter.

A regulated, low ripple, high voltage of very low current capability is applied by instrument on a DUT (device under test). The leakage current in nA or pA (picoamps, nanoamps) is measured and readout, The Innovation i did was to measure the current in Vref and not Vin of ICL7107, this made the 1/x computation.
   
Winding Insulation Resistance Measurement

Also using the ICL7650 Chopper Stabilized amplifier must be done as shown in data sheets with grounded guard rings. pA will leak on the PCB itself if layout is not done keeping this in mind

Tera Ohm Meter and
                        Insulation Tester

Megger or Insulation Tester

Decades ago, when a customer found that my Tera Ohm Meter expensive, He suggested the specs for this low cost scaled-down model. This was found useful for people sub-contracting Telecom Equipment Manufacturing.


Megger or Insulation Tester