器件名称: DI-128
功能描述: 35 W (75 W Peak) Variable-speed DC Motor Drive
文件大小: 843.03KB 共2页
简 介:Design Idea DI-128
PeakSwitch
Application DC Motor Drive Device PKS606Y
35 W (75 W Peak) Variable-speed DC Motor Drive
Power Output 35 W (75 W Pk) Input Voltage 90-265 VAC Output Voltage 12 V Topology Flyback
Design Highlights
Replaces a two-stage, linear power supply and chopper circuit with a simple, single-stage design Eliminates the chopper circuits normally used to achieve variable-speed control of DC motors Motor speed is controllable by a small potentiometer or a 3.6 V to 10 V variable DC voltage Low component count: only 47 parts Efciency: ≥77% (at a load of 35 W) Meets EN55022 B conducted EMI limits ON/OFF control scheme is stable over the entire motor speed (output voltage) range
supplied 3.6 V to 10 VDC voltage source (connected to J4). The motor speed controls vary the output voltage of the supply. The controller in U1 receives feedback from the output and enables or disables the switching of its integrated MOSFET. Regulation is maintained by disabling or skipping MOSFET switching cycles. The output voltage is sensed across the series string of R12, Zener diode VR2 and the LED in U2 (in parallel with R13). As the output voltage rises above the VR2 conduction threshold, the current that ows through the U2 LED turns on transistor Q3. As Q3 pulls current out of the EN/UV pin of U1 switching cycles are skipped and less energy is transferred to the output. Once the output voltage falls, switching cycles are enabled again. A bias winding (T1, pins 4 and 5) on……