Home Made Power Supply. Home Utility Circuit 27

2AThis Homemade Power supply is useful for the Electronics hobbyists and service persons to test and troubleshoot the circuits. It gives six stage well regulated output power with a current of 800 mA. Its construction is “Open type” as it is home made. You can make it like a professional power supply by fixing inside a box with connectors for tapping the output.
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Bread board power supply. Home Utility Circuit.16

1AThis Project is for the Circuit designers. Lot of projects are experimented in Bread board and Perf boards before finalising the project. So these projects need a power supply to test. Usually a 9V PP3 battery is used to power the bread board. So here is a compact Portable Power supply unit for the Bread board experiments. The Power supply includes
1. A charger indicator for the 9V rechargeable battery
2. A battery voltage monitor
3. Output sockets for charging and tapping power to bread board.
4. An LED light for the bread board working
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Over Voltage Protector. Simple Design 9


This is one simplest form of Over voltage Protector for the Bread board power supply. Usually we use 12 volt DC power supply to power the bread board. If the CMOS devices are used in circuit assembly, over voltage can damge them permanatly. This circuit limits the voltage to the bread board to 12 volts. If the voltage increases above 12 volts due to a high voltage surge in the AC lines ,the circuit cut off the power to the bread board. It can also be used in any device like Chargers that works on 12 volt DC .
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Portable Power supply. Design Note 44

Hacked my Laptop battery and charger to make a Portable power supply. My old Laptop was irreparably damaged leaving only a good battery. It is a high performance 12 volt Lithium Ion rechargeable battery that can backup more than 2 hours a laptop and many hours for circuit boards and LED lights. So I made a Portable power supply using the battery. So don’t discard the battery and charger if your Laptop fails permanently. Both battery and the charger costs around Rs. 2000.It can be utilized for making a Power supply or LED lamp. So it is the  good power supply I ever made because it is running on battery and output is fully regulated.
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Power Supply for Projects. Design Note 43

IMAGEFor bread board assembly of Micro controller and Arduino projects ,we need  well regulated  5 V and 3.3 V DC power supply. Here is the simple but efficient regulated power supply that gives four stage power outputs  – 12 V unregulated, 9 V, 5 V and 3.3 V regulated DC .
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Transformer less Power supply Problems. Design Note 39

To reduce size, and cost, Transformer less power supply is now used. If it is a well regulated SMPS power supply, output will be stable. But simple Transformer less power supply is not ideal for many circuits as observed in my experience. I have designed different types of Transformer less power supply but none of them is showing good performance. It can be used to power simple circuits like LED lighting. If sensitive semiconductors are present in the circuit, this kind of power supply creates many problems including erratic response. This is very high in sensor based circuits and oscillators. So to get a perfect output voltage, it is ideal to use a Transformer based power supply or SMPS. These are the problems I noticed in the Transformer less power supply.
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Short Circuit Indicator for Bread board. Design Note 38

Here is a solution to protect your circuit assembly on Bread board. Usually we test the working of a circuit first on bread board before making the PCB assembly. Sometimes due to mistake in wiring, valuable components may destroy through short circuits. With the power on , we still continue the trouble shooting which may further destroy many components. Only after sensing heat or burning, we realize the problem. So here is the simple solution to assemble the circuit on bread board safely. If there is any short circuit in the bread board, the power to the board will cut off and Red LED lights. So immediately we can detach the board from power supply.
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