Rolling Shutter Motor Control Circuit

This is a circuit for an electrically operated rolling shutter usually has a standard control panel with a three-position switch: up, down and stop. If you would like to automate the opening and closing with a time controlled switch, a few additional wires will have to be connected. Typically, the controls are implemented as indicated in the schematic ‘Normal Situation’. This is the figure of the circuit;

If this is indeed the case, then you can see in ‘New Situation’ how the shutter can be automated with a timer. There is only one method to determine the actual schematic of your control circuit, and that is to open the control box and using an ohmmeter, pencil and paper to check out and draw the circuit. Make sure you turn the power off first though! Connect a 230-V relay (with both the contacts and the coil rated 230 VAC) to the timer. The changeover switch between automatic and manual control needs to be rated 230 VAC as well and may not be a hazard for the user. The relay and switch are preferably fitted in a plastic mains adapter enclosure with built-in plug, which is plugged into the timer. It is a good idea to check first if this will actually fit. Because of the manual/automatic-switch, the operation is completely fail-safe and misunderstandings are out of the question. The switch prevents the issue of conflicting commands (with disastrous consequences) when, for example, the shutter is being automatically raised and manually lowered at the same time.

3 Phase AC Motor Speed Control Circuit

Controlling the speed of three phase ac motor is done by controlling the frequency of the power line supply,  since the motor is synchronized with the line frequency. Three phase ac motor speed controller is actually nothing more than three phase sine wave power inverter with variable frequency. The three phase power inverter is a complex circuit, but fortunately there is an integrated circuit chip for this purpose. This is the figure of the circuit;

For the final motor driver circuit, you can see the component values are shown only for OB2 channel, but the others are similar. This 3 phase ac motor controller use optical isolation, so you must be careful in designing the layout, to make a clear separation between low and high voltage network. This separation is useful for minimizing the risk of hazardouz electrical shock.