Rongge

This is a very simple circuit of a dimmer, ie a controller LED brightness, which is powered from the USB port of a PC and a connection is very simple. The resistor R1 sets the maximum current of the LED with the maximum potentiometer, resistor R2 should have a resistance of 10x to 100x greater than R1. The table shows which components to use in accordance with the selected LED. Dimmer-Brightness LED Driver Circuit Diagram

A very simple 6 channel low cost led driver electronic circuit project can be designed using the MCP34845 LED drivers manufactured by Free scale Semiconductor.The MCP34845 LED drivers operates from 5 to 21 volts and is specially designed for use in back lighting LCD displays from 10" to 17"+ for devices like : PC Notebooks , Net books , Picture Frames , Portable DVD Players , Small Screen Televisions , Industrial Displays , Medical Displays , etc. 6 Channel LED Driver Circuit Diagram The MCP34845 LED drivers is capable of driving up to 16 LEDs in series in 6 separate strings.PWM dimming is performed by applying a PWM input signal to the PWM pin which modulates the LED channels directly.Main features of this driver circuit project are : input voltage of 5.0 to 21 V , boost output voltage up to 60 V, 2.0 A integrated boost FET , fixed boost frequency - 600 kHz or 1.2 MHz , OTP, OCP, UVLO fault detection , LED short/open protection , programmable LED current between 3.0 mA and 3...

The circuit is based on a 555 IC (Bipolar or CMOS) for sensing the minimum and maximum water levels and turns a MOSFET on/off which directly controls a 12V DC pump motor. Or, it can power a relay coil to switch high currents/voltages, DC or AC. ‘Trigger’ and ‘Threshold’ pins (2 & 6) are used to detect the maximum and minimum levels, respectively. The two voltage comparator op-amps inside the 555 control the output, turning it on/off. Looking at the circuit diagram you will notice that the ‘Trigger’ pin (2) is marked ‘HIGH probe’, despite being triggered (output goes HIGH) when the voltage drops below 1/3 of the supply voltage and, the ‘Threshold’ pin (6) is marked ‘LOW probe’ while it is ‘reset’ (output goes LOW) when the voltage rises above 2/3 of the supply voltage. The circuit works as follows: Three (3) probes are immersed in the vessel. (usually from the top) One is the ‘GROUND’ probe, going to the level a little lower than the minimum desired level. This is the ‘common’ (or ‘...

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 ...

The circuit above is  a circuit of drivers to control high voltage using the relay. Relay is controlled by an NPN transistor , its that works on 5V voltage and has diode in it, if the relay does not have s diode should be given with diode 1N4007 . Pin relay to  move the switch connected to V+ 5V and other is connected from driver NPN transistor , the base od the transistor may have input such us from circuit of infrared to control the distance, or with some other input. After the transistor was input  and the collector had output a voltage of the switch relay will work, and voltage that in switch relay ready to use. To cut off switch eliminates enough voltage input at the base transistor , the collector will not remove the voltage , and switch are automatically disconnected.