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How It Works

Here is a technical description of the board, describing in detail the way the board functions and what each part does. It can be helpful if one has a wish to build one or if the need to troubleshoot arises.

This video includes an overviw of the servo unit and a detailed description of how the controller works electronically.

How Does It Work?

Basically the controller board is a servo driver. It takes the voltage signal from the TEMP control knob and compares it to the voltage signal from the feedback pot on the servo and runs the servo motor until the two voltages balance. The other components are there to support the components that make that happen.

There are 2 power supplies, one +5V regulated supply for the control of the motor driver and another +/-5V supply for the LM741 op-amp. Also there is the LM741 op-amp that is set up as a comparator to compare the voltages of the TEMP and the feedback pots and there is the output section that drives the motor.

Here are downloads of the various wiring schematics and a parts list for the standard board. There is also a simple way to drive the servo using a DPDT switch. The switch will drive the servo from limit to limit and can be used permanently as an alternative to the electronic controller if so desired.


Wiring Schematic for Standard, SMD and 5X20 Boards

Parts List for Standard Board

Wiring Schematic for Relay Board

Wiring Schematic for TC4420 H Bridge Board

DPDT switch to control the servo

Wiring connections