Thermal Head Power Supply Control Circuit - Brother SC-2000 Service Manual

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Thermal Head Power Supply Control Circuit

Fig. 3.3 shows the thermal head power supply control circuit.
Fig. 3.3 Thermal Head Power Supply Control Circuit
Receiving the 25V input from the power supply PCB, the thermal head power
supply control circuit generates the output voltage of the switching regulator (#17:
MC34166T) according to the thermal head voltage control signal output from P61 of
the CPU. By adjusting the volume resistance at VR1 (1K ), the thermal head
voltage is set at approximately 19V.
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