3 results about "Electrolytic capacitor" patented technology

The invention provides a switching power supply device capable of ensuring the transient recovery of the voltage discharge of an electrolytic capacitor after the rectifying process, without the addition of power consumption. The switching power supply device comprises a rectifying circuit used for rectifying the AC voltage; an electrolytic capacitor used for rectifying and smoothing the AC voltage; a transformer used for applying a smoothed voltage onto the electrolytic capacitor; a switching element connected to the transformer (T); and a control circuit (Z1) used for enabling the switching on/off of the switching element. The control circuit (Z1) is composed of a start-up circuit (Z10) and a discharge circuit (Z14). The start-up circuit (Z10) is used for supplying the voltage of the electrolytic capacitor to the Vcc terminal of the control circuit (Z1). The discharge circuit (Z14) is connected with the Vcc terminal and is used for discharging the transient recovery voltage of the electrolytic capacitor.

The invention discloses an LED drive device with stable performance. The LED drive device comprises an input protection circuit, a step-down circuit, a rectifier and filter circuit and a voltage-dividing and current-limiting resistor, which are electrically connected, wherein the voltage-dividing and current-limiting resistor is used for carrying out current limiting on an LED light source circuit and carrying out current limiting protection on an LED, so that the LED works under the drive of stable voltage and current; and the service lifetime of the LED is ensured. A filter capacitor in the rectifier and filter circuit is a tantalum electrolytic capacitor; and the filter capacitor is relatively small in volume and stable in performance under the conditions of the same withstand voltage and electric capacity, can still keep good electrical performance after long-time working and can prolong the service lifetime of an LED drive circuit. A discharge chip resistor is arranged in the filter capacitor; and after a power supply is cut off, the chip resistor can discharge the electricity stored in a capacitor core within a short period of time, and reduces the voltage of the capacitor core to zero, so that bleeder resistors do not need to be connected with two ends of the filter capacitor in parallel; and the circuit for driving the power supply is relatively simple.

The invention discloses a household early earthquake electronic alarm device. The household early earthquake electronic alarm device is characterized by comprising a 6V direct-current power source, two paths of monitor probes, a bridge balance circuit and a buzzer driving circuit. The bridge balance circuit is composed of the two paths of monitor probes, a PNP type transistor VT1, a PNP type transistor VT2, a resistor R3, a resistor R4, a linear potentiometer RP, a resistor R5 and an electrolytic capacitor C1, and a base electrode of the PNP type transistor VT 1 and an emitting electrode of the PNP type transistor VT2 are connected with the two paths of monitor probes respectively. The buzzer driving circuit is composed of an NPN type transistor VT3 and a buzzer HA. According to the technical scheme, the circuit structure is simplified, and the requirements for high monitor sensitivity and reliable work performance are achieved. Once one certain path of monitor probe is triggered, the alarm device gives an alarm through the buzzer immediately, the bridge circuit is automatically kept locked once an alarm signal rings out, and the phenomenon of error alarming or missing alarming can be basically eradicated.