These scopes were made to operate over a wide temperature
range. A thermistor's cold resistance can become very high
at the low end of the temperature range, perhaps high enough
to make it unlikely to start charging the capacitor. So,
tektronix added a shunt resistor to help define the maximum
resistance (minimum starting current) in series with the switch.
-Chuck Harris
n4buq wrote:
toggle quoted message
Show quoted text
Hi Chuck,
Where does a shunt resistor go relative to the thermistor? I thought the thermistor was the only component in an inrush current limiter. Is that incorrect?
Thanks,
Barry - N4BUQ
<snip>
To cure this inrush problem, tektronix put a thermistor,
with a shunt resistor in series with the power switch.
<snip>
-Chuck Harris
