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%.
3 thoughts to “Time Electronics 404S & 404N DC Millivolt Source Teardown & Review”
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.
Could you please scan and share the circuit diagram? I’d love to take a look.
Hello Barry, please share the circuit diagram for the Time Electronics 404S & 404N.