12 VDC TO 117 VAC / 60HZ POWER INVERTER

12 VDC TO 117 VAC / 60HZ POWER INVERTER
Capacitor C5 and potentiometer R12 figure out the frequency of the output signal at pin number 3 of IC1, the 555oscillator. The output signal is differentiated by C3 and C4 before it's input to the base of power transistors Q1 and Q2 through diodes D1 and D2, respectively. The signal from IC1 is adjusted to 120 Hertz, because the flip-flop created by transistors Q3 and Q4 splits the frequency by two. (more…)

12 Volt Battery charger

12 Volt Battery charger
The following schematic is a high-performance battery charger for gelled electrolyte lead acid battery. Battery charger quickly recharges lead acid battery  and shuts off at a full charge. Innitially, charging current has limitations to 2 Ampere. While the battery voltage goes up, current to the lead acid battery  decrease, and if the current has decrease to 150 mA, the battery charger changes to a lower float voltage protecting against overcharge. (more…)

-15 V 1-A Regulated Power Supply

-15 V 1-A Regulated Power Supply
The actual supply should get -20 V coming from rectifier/filter that is given to the collector of Darlington PNP-type pass transistor, a TIP 105. The base drive for the TIP105 is supplied  via resistor R5. The base of the TIP is driven from Vz terminal at pin 9, this is anode of 6.2 V zener diode which links with the emitter of uA 723 output control transistor. The way of providing the positive feedback needed for feedback action is

+15 Volt 1 Amp Regulated Power Supply

+15 Volt 1 Amp Regulated Power Supply
The actual supply takes +20 Volt Dc through the dioda bridge or filter part. This can be given to pins 11 and 12 on ua723, and also for the collector  2N3055 series-pass transistor. All the output voltage will be sampled through R1 and R2, giving around 7 Volt relating to ground at pin 4. The reference terminal at pin 6 is linked right to pin 5, the noninverting input of the error amplifier. (more…)

Thermaltake Toughpower XT TPX 875M – 875 watt

Thermaltake Toughpower XT TPX 875M – 875 watt
With the Thermaltake Toughpower models has been present for some time on the PSU market. The series is now completely revised and given the code "XT" as a sign of a high-quality, powerful and more efficient psu, a modular cable management and a large and quiet 140mm fan. This is automatically controlled and has a follow-up control. So it turns on for a time after the the computer is inactive to handle the rest of the heat from the

750 Watt Cooler Master GX Series Computer PSU

750 Watt Cooler Master GX Series Computer PSU
With the GX-Series Cooler Master released a new PSU. The model designed as an inexpensive high-power supply, initially with three power levels are available. On wide range of accessories is so deliberately in order to offer an attractive price level. Powerful 750-watt power supply, the GX Series from Cooler Master with 60-A single-rail and 4x PCIe. On the other side is also installed complex electronics, which is reflected in the higher efficiency and the extremely long warranty period of 5

530 W Be Quiet Dark Power L7 power supply

530 W Be Quiet Dark Power L7 power supply
Be quiet! Power supply features a quiet operation, a very high quality workmanship, high efficiency and extensive features. With these features, the producers lined up in the Topriege is therefore one of the most popular brands in this segment. With Pure Power L7 series expands be quiet! its offering to now specially priced models with simple facilities, but the same high performance, efficiency and good workmanship. (more…)

Mobile Charger with Voltage Converter

Mobile Charger with Voltage Converter
The circuit allows a simple and safe charging of 1-10 Ni-Cd or Ni-MH cells from a 12V source. The voltage converter can be operated at 6V, in this case is the max. output voltage 12V (no load). The performance can be improved through the use of Schottky diodes (D2/D3). D4 (LED) can omitted if you dont want any indicator. An astable Mutivibrator generates the oscillation frequency. At the output (pin 3) connected the voltage doubler. At C5 is idling