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.
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).
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
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.
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
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