双线灯闪光灯电路--Two-wire Lamp Flasher Ideal to operate 3 to 24V DC exisTIng on-circuit lamps LED operaTIon is also possible Parts: R1______________6K8 1/4W Resistor C1____________220΅F 25V ElectrolyTIc Capacitor D1___________1N4002 100V 1A Diode Q1____________BC557 45V 100mA PNP Transistor LP1___________Existing filament Lamp: any type in the range 3-24V 10W max. SW1___________Existing On-Off switch B1____________Existing V DC source: any type in the range 3-24V suited to the lamp adopted
Device purpose: This circuit has been designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit between existing lamp and negative supply.
Notes: Break lamp(s) to negative supply connection(s), then insert the circuit between existing lamp(s) connection(s) and negative supply (respecting polarities!). C1 value can be varied from 100 to 1000΅F or higher, in order to change flashing frequency. Although rather oversized, this circuit can also drive any LED, providing a suitable resistor is fitted in series with the light emitting device. The resistor should be in the range 47R to 2K2, depending on supply voltage. |
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