Category Archives: Practical DIY Electronics

Electrical Electronic Design, Electrical Testing and Verification, Practical DIY Electronics

Dimmer Switch Replace How to Install

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Dimmer switch replace for small appliances like laboratory microscopes, slit lamps, and others as you may think of, Sometimes, the circuit is bad and its taking too much time to find out the problems in the course of diagnose. Find below the schematics diagram for a dimmer switch replace suitable for a low voltage appliances. It is a  Pulse Width Modulation based module suitable for light source of Microscope, Slit Lamps and portable light source. Meanwhile, for small DC electric motor and lots more.

You could actually ask for a replacement dimmer switch from the manufacturer of your product, But if you still have warranty on the appliance, the manufacturers or suppliers would be in a position to help in the repair or replacement.


dimmer switch replaceAbout the Schematic

The circuit module above consists of three circuits put together. The circuits are 12 volt positive regulator, an oscillator, and a voltage comparator. Other are an integrator, and a driver. The oscillator and the integrator employs an LM324. The comparator is also one of the LM324 package with supporting components.

For this circuit to work, you need a source of unregulated dc power supplies or a battery. Besides, the PSU should be more than voltage of the ic regulator. For example, if the Ic voltage regulator is 12V as shown in the schematic, then, the PSU voltage should be at lear 2.5 volt more than 12 volt. That is, 14.5 volts. Learn more about unregulated power supply unit.

Meanwhile, for more information regarding for specifications; theory; construction; alignment/calibration/configuration; how to use and Bills of Quantity, check here Motor Speed Controller and or DC Light Dimmer (2016_06_01 10_11_06 UTC). 

We can adapt the simple dimmer schematic to control high power load by simply change few components. The main component to change is the Field Effect Regulator (FETs) and the fuse.

Practical DIY Electronics

Transformer instructions

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Basic Transformer Action

Transformer instructions give answers to basic questions about transformer. This include principles behind transformer or transformer actions, transformer circuit, connections, current, design calculation, transformer functions and lots more. You will find transformer in many equipment such as UPS, Audio amplifier, DC power supply or Rectifier. Transformer in circuit use includes:

  1. Isolation Protection
  2. ⚡ Voltage Conversion as you normally encounter in distribution and power supply
  3. Impedance Matching Transformer as employed for instance in amplification and
  4. Power Control
Transformer Winding Direction

Some people confuse when they encounter transformer with multiple leads. This they do when troubleshooting or fabricating.  Some of the reasons are they don’t know which one is primary or secondary, not only this, two windings winding may be  out of phase with the other, and if use as it is without consideration  and figuring it out, you get wrong output. Some circuit diagram include transformer instructions on windings. You need to check phase arrangement of the coil before connecting to the rest of the circuit. There is usually marked to indicate this. You can confirm this if you have a circuit diagram to work with and for more information on transformer, check out this video. Send us a reply or questions on the topic for more detail understanding.

Transformer instructions

Transformer Instructions Testing and Repair

Transformer may experience a short or open-circuit depending on the stress to which it encounter. The pry side is more vulnerable if there is a surge especially if it is a step down transformer because it usually has more turns at high resistance. Meanwhile, any problems from the secondary side will reflect on the primary.  To keep your transformer save, use a fuse before the primary and after the secondary. Never bypass any fuse, some manufacturers equipped their transformer with thermal fuse in the primary; in this case when you observe an open in the pry coil look for this. It is cheaper to replace the thermal fuse than the entire transformer. For more on transformer used in electronics and projects CONTACT US.