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Simple and cheap, the circuit built based on well-known IC regulator LM317 with current booster of power transistor 2N3782. Don’t forget to add heatsink especially for power transistor 2N3782.

Circuit Diagram Description Friends that seek 5V 10A power supply circuit small-sized and build easy. I begs for to advise this circuit. It is 10A switching regulator by use IC L4970A. Then build easy as an example integrated readymade circuit. Important point be power supply input must have 10A current sizes then can give power get enough. The detail is other of the circuit almost must not fine to decorate anything. If friends take an interest try seek buy the integrated circuit and other equipment. come to try build immediately yes. Image Source www.st.com 

The schematic above can be used for supply on color TV for all type TV circuit. But we need to know how much voltage needed by the circuit of color Television. To set the output voltage, the setting on VR1 1K ohm. Required input voltage 300V DC which is already on TV circuit, so we just take a 300V dc voltage existing on the TV circuit, and for a circuit supply voltage on our TV cut the line PCB and connected with this  universal switching power supply.For the transformer we can use the TV regulator transformer. Part List : R1 = 33R 5W R2 = 330R 1W R3 = 2K2 R4 = 47K R5 = 2K7 R6 = 22K R7 = 390K R8 = 47R 1W C1 = 100uF 25V C2 = 1n2 2KV C3 = 18n C4 = 18n D1 = 1N4148 D2 = 1N4148 D3 = ZD 12V D4 = 1N4007 D5 = 1N4007 VR1 = 1K ZD1 = Zener 6V T1    = TV regulator transformer Q1   = K2847 Q2   = C2328A PCB line Finishes circuit

You can pick up a 3½-digit digital volt-meter module nowadays for a little as a couple quid. This is a simple and expensive way to fit out a piece of equipment with an instrument. Most modules are based on the well-known ICL7106 IC . They operate from an ordinary 9-V battery, and they only provide a fixed measuring range (200 mV or 2 V). The accessory circuit described here converts a DVM module into a voltmeter with 20-V and 200-V measuring ranges, with the added bonus of automatic range switching. This requires a ground-referenced symmetrical supply voltage (±5 V) instead of a battery. An inexpensive TL431C is also used to generate an adjustable reference volt-age from the supply voltage. The circuit described here uses an LCD module with a fixed measuring range of 200 mV. It has three pins for driving the decimal point; two of them are used here. Automatic Range Switching Schematic This is how the circuit works: IC1 converts the voltage to be measured by the DVM m...

This circuit is a simple battery-powered switching regulator provides 5V out from a 9V source with 80% efficiency and 50-mA output capability. When Q1 is oon , its collector voltage rises , forcing current trhough the iinductor. The output voltage rises , causing A1's output to rise . Q1 cutts off and the output drops low enough for A1 to turn Q1. The 1 uF capacitor ensures low battery impedance at high frequencies , preventing sag during switching. See schematic diagram below :

Amateur radio has been somewhat slow to accept switching power supplies for powering communication equipment. This is a pity, because "switchers", as they are often called, offer very attractive features, like small size, low weight, high efficiency, and low heating. True, they are generally more complicated than linear power supplies, but this is easily compensated by the fact that they can be built for a lower cost. Some early switchers produced an objectionable amount of RF noise, bringing the whole switching technology into bad reputation. But by proper design techniques and careful EMI filtering it is possible to build very quiet switchers. In this article I will describe the construction of a switching power supply designed to power a complete ham station, with several radios and accessories. This power supply produces 13.8V regulated to better than 1%, at a continuous load current of up to 40A. It has current limiting, making it appropriate for direct connection to a 1...