Light emitting diode display circuit 2b

Light-emitting diodes can also use capacitors to reduce voltage . If capacitors are used to reduce voltage, the power consumption of the entire circuit is almost close to
that of the light-emitting diodes. However, when using capacitors to reduce voltage, some measures must be taken to prevent the light-emitting diodes from breakdown due to the instantaneous voltage impact of the capacitors. The circuit
    using AC drive and capacitor voltage reduction is shown in Figure 13-2.
    The selection of components is as follows: the diode VD uses 1N4001 to protect the light-emitting diode
(reverse voltage); for the AC 220V power supply, the capacitor Cl uses polyester capacitor o. lptF/400V, C2 selects BP type bipolar capacitor 22"F/
16V as the absorption branch of the instantaneous impulse current, circuit R selects 2.ZMfl, 1/8W resistor; as the
discharge , resistor R selects 6. 2k0, 1/2W resistor.