Schematic diagram of HL202 used in DC motor chopper speed regulation system

Practical examples HI. The unique and ingenious design of 202 allows it to be easily used for DC
motor speed regulation, PWM forward
and reverse reversible speed regulation, position servo systems, frequency conversion speed regulation of AC motors, and switching
power supplies where the main power device is powered by a high-power transistor. It replaces the discrete power transistor drive circuit in fields such as sine wave inverter power supply and so on,
so that the driven power transistor can work with high performance. Figure] 2-24 shows the schematic diagram of a DC motor chopper speed regulation system
using SG3524 as a PWM pulse generator and driven by HI4202 . In the figure, the operational amplifier inside SG3524 is used to form a closed-loop regulator, and its internal comparator implements centralized overcurrent protection. Therefore, the system has better speed stabilization effect and larger speed regulation range. Win application, HI. The positive power supply voltage for 202 work is selected as 9V, the negative power supply voltage is selected as 6V, and the resistor R is selected. Select 100, resistor R: 1sn, and the delay time of undersaturation protection is selected 1.5ys, thus determining C. for. ． 22yF. Since the driven power transistor has a capacity of 50A and the DC bus voltage is 2ZOV, the HL202 direct output is used to drive the GTR. The Shaanxi recovery diodes used for Baker clamping and desaturation detection are both 800v 1A MUR180. The recovery time is 35ns, and the feedback signal in the figure comes from the secondary side of the Hall voltage sensor TV.