USB Lamp Circuit
Created: Jun 22, 2015
No description available.
This project is a simple USB lamp circuit that effectively lights when connected to a PC or laptop or any devices that are USB ready. It uses the TE Connectivity’s standard plug or receptacle providing a multi function, single cable solution for USB. This TE's connector system accommodates the two deferentially driven data wires that provide bi-directional, simultaneous signals for full speed (12Mbps) or low speed (1.5Mbps) used in universal series bus (USB) systems.
The circuit operates from the 5V available from the USB port. The 5V from the USB port is passed through current limiting resistor R2 and transistor Q1. The base of transistor Q1 is grounded via R1 which provides a constant bias voltage for Q1 together with D2. The diode D1 prevents the reverse flow of current from battery. The capacitor C1 is used as a noise filter. The two white LEDs are used here for the lamp, you can also use a 2V torch bulb instead of LEDs. The LED D3 indicates connection with USB port.
This USB powered lamp is very useful to light the desktop during power failures or when an enough light is only needed. This portable device may be a good alternative for an energy saving light source. This can be connected to desktop, laptop, keyboards, printers, scanners and any other related devices.