Rongge

The current drain of the regulator is minute compared with that of, say, a 78L05: at an input voltage of 9 V and open-circuit output, it is just under 50 µA. The circuit consists of a straightforward bandgap reference based on T1 and IC1, followed by an amplifier formed by IC2 and T1. The reference voltage is about 1.22 V, which is raised by IC2 to 5 V. The output voltage can be set to exactly 5 V with P1. The input voltage may lie between 6.5 V and 30 V. The maximum output current with the present configuration and component values as specified is about 10 mA. For optimum performance, T1a and T1b need to be identical, which is why a dual transtor Type MAT02 is used. Other types that may be used are the MAT01, SSM2210 or LM394. In principle, two standard BC transistors may be used, provided they are selected for identical threshold voltage. Circuits IC1 and IC2 are programmable op amps Type OP22. In the case of IC2 this has the benefit that the peak output current can be set readily by...

All miniature electronic devices operate off batteries. Some of them need higher than the standard battery voltages to operate efficiently. If the battery of that specific voltage is unavailable, we are forced to connect additional cells in series to step up the DC voltage. Thus, the true meaning of miniaturisation is lost. A simple way to overcome this problem is to employ a voltage doubler, if the device under consideration can operate at a small current. Here we present a low-power voltage doubler circuit that can be readily used with devices that demand higher voltage than that of a standard battery but low operating current to work with. The circuit is quite simple as it uses only a few components. Yet, the output efficiency is 75 to 85 percent along its operating voltage range. The available battery voltage is almost doubled at the output of the circuit. Here IC1 is wired as an astable multivibrator to generate rectangular pulses at around 10 kHz. This frequency and duty cycle of...

This is a simple project of ESR and Low Resistance Test Meter Circuit Diagram. As electrolytic capacitors age, their internal resistance, also known as "equivalent series resistance" (ESR), gradually increases. This can eventually lead to equipment failure. Using this design, you can measure the ESR of suspect capacitors as well as other small resistances. Basically, the circuit generates a low-voltage 100kHz test signal, which is applied to the capacitor via a pair of probes. An op amp then amplifies the voltage dropped across the capacitor’s series resistance and this can be displayed on a standard multimeter. In more detail, inverter IC1d is configured as a 200kHz oscillator. Its output drives a 4027 J-K flipflop, which divides the oscillator signal in half to ensure an equal mark/space ratio. Two elements of a 4066 quad bilateral switch (IC3c & IC3d) are alternately switched on by the complementary outputs of the J-K flipflop. One switch input (pin 11) is connected to...

Circuit diagram: Low Voltage Audio Power Amplifier LM386 Datasheet for LM386: Download

The circuit of battery indicator consists of a 741 operational amplifier configured as a voltage comparator, using a zener diode as a reference voltage pattern. This circuit can be adapted to work with battery between 6 and 18 V, and the only changes required would be a lower Zener voltage and current limit resistor in the case of low voltage below 9 V and greater for higher voltages.The adjustment is made with R2 which can be a trim pot. Dimmable Low Battery Indicator Circuit Diagram

The UCC27518 and UCC27519 single-channel, high-speed, low-side gate driver device is capable of effectively driving MOSFET and IGBT power switches. Using a design that inherently minimizes shoot-through current, UCC27518 and UCC27519 are capable of sourcing and sinking high, peak-current pulses into capacitive loads offering rail-to-rail drive capability and extremely small propagation delay typically 17 ns. The UCC27518 and UCC27519 provide 4-A source, 4-A sink (symmetrical drive) peak-drive current capability at VDD = 12 V. The UCC27518 and UCC27519 are designed to operate over a wide VDD range of 4.5 V to 18 V and wide temperature range of -40°C to 140°C. Internal Under Voltage Lockout (UVLO) circuitry on VDD pin holds output low outside VDD operating range. 4A High-Speed Low-Side Gate Driver  Circuit Diagram Features Low-Cost, Gate-Driver Device Offering Superior Replacement of NPN and PNP Discrete Solutions Pin-to-Pin Compatible With TI’s TPS2828 and the TPS2829 4-A Peak ...

These amplifiers using IC KA2202 and KA2207, which has a power output of 2.3 Watt berimpedansi 4 ohms. Minimum supply voltage and maximum 5Volt 20Volt. See schematics and component list below. Part List  R1 = 100K R2 = 56R R3 = 56R R4 = 1R Use 1/4 Watt resistor C1 = 100uF C2 = 100uF C4 = 100uF C5 = 470uF C6 = 100nF C7 = 470pF C8 = 2,2nF C9 = 100uF U1 = KA2202 , KA2207