Channel 2
DACoutput
Can vary
between10
and5000mil‐
livolts
4-20milliamp output fromPeakSimple
October 2013
The 4-20ma circuit is located on the
Model 333A/D board.
The circuit itself looks like the dia-
gram at right.
The channel 2DAC outputs a voltage
which is converted to a current by the
LM324 op-amp and power transistor.
If theDAC output is 400millivolts
then the current is 4ma. If theDAC
ouput is 2000millivolts then the cur-
rent is 20ma.
InPeakSimple, channel 2must be
ACTIVE for this towork.
100ohm
resistor
1N4004
diode
LM324op‐
amp
+
external
power
supply
GC chassis
ground
External
sense
resistor
TIP100
transistor
1N4004
diode
