Time Electronics 404S & 404N DC Millivolt Source Teardown & Review

Here we review two Time Electronics Ltd. DC Millivolt Source calibration units. They use a precision reference zener diode, low temperature coefficient resistors and thumb switches to select a precise voltage accurate to 1 Micro Volt. They have 3 ranges and an accuracy of ± 0.05%.

2 thoughts to “Time Electronics 404S & 404N DC Millivolt Source Teardown & Review”

  1. No pre-aged zenner diodes or chopper op amps in the sealed module. One MAX63** voltage reference and
    one OP07 op-amp. A few driver transistors in dc configuration and that was about it. I know because I have the circuit diagram.

    Ex Merchant Navy Calibration Engineer.

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