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Showing posts with the label Lights

Sound Activated Lights

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This diy sound activated lights circuit turns a lamp ON for a short duration when the dog barks (or a relatively strong sound) giving an impression that the occupants have been alerted. The condenser microphone fitted in a place to monitor sound and generates AC signals, which pass through DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 along with transistor T2 amplifies the sound signals and provides current pulses from the collector of T2. When sound is produced in front of the condenser mic, triac1 (BT136) fires, activates lights and the bulb (B1) glows for about two minutes.  Sound Activated Lights Circuit Diagram Assemble the sound activated lights circuit on a general purpose PCB (circuit board) and enclose in a plastic cabinet. Power to the sound activated switch circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circui...

Car Interior Lights Delay Circuit Diagram

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Most cars do not have delayed interior lights. The circuit presented can put this right. It switches the interior lights of a car on and off gradually. This makes it a lot easier, for instance, to find the ignition keyhole when the lights have gone off after the car door has been closed. Since the circuit must be operated by the door switch, a slight intervention in the wiring of this switch is unavoidable. When the car door is opened, the door switch closes the lights circuit to earth. When the door is closed (and the switch is open), transistor T1, whose base is linked to the switch, cuts off T2, so that the interior light remains off. When the switch closes (when the door is opened), the base of T1 is at earth level and the transistor is off. Circuit diagram: Capacitor C1 is charged fairly rapidly via R3 and D1, whereupon T2 comes on so that the interior light is switched on. When the door is closed again, T1 conducts and stops the charging of C1. However, the capacitor is discharge...

Operating Color Lights on USB

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This project is a remake of an old discolights pod. Original 24V 5W bulbs are changed to 230V 40W with E14 thread. Original driver board has non-typical signal input. This driver is based on the FT245RL chip, a USB-LPT converter – so you can use it with PC applications such as discolitez. Low voltage part is supplied directly from the USB so there is no need to to use any transformer…   Device uses a MOC3041 optotriac and a BT136 triac in a standard application to drive bulbs. Note if you want to use stronger bulbs, like 100W or more, you need to use some little radiators to cool down the triacs. There are 4 channels, 3 are used for bulbs and 4th is used as an extra 230V output – in this case for a mini strobe. You can find 4 goldpins on board, these are a 4 extra output channels – so you can expand device to another optotriacs and triacs to use 4 more 230V devices. To your own safety, use a proper fuse, and remember that device works on a 230V potential. You can use it with 110V d...