Free homemade LED lamp circuit diagram

Posted on Mar 28, 2007

Also known as the Free lamp (ie, online sellers, commonly known as Myanmar lamp), because it takes into ordinary household fixed telephone line voltage power to do, no batterie

Free homemade LED lamp circuit diagram
Click here to download the full size of the above Circuit.

s or AC power, the tail crystal head into a telephone extension interface can be illuminated without the other pay the electricity bills, do not worry about power outages. Also can serve as phone calls flashing lights. Listening is not timely to remind the good old people answer the phone, because after phone off hook LED light will turn off, but also help you discover whether others Daoda phone also has some anti-lightning protection. However, because the product is used in the telecommunications room phone belongs to feed power supply, once obtained from the use of too much current will inevitably affect the phone calls and send and receive faxes, especially likely to cause frequent dropped calls when ADSL broadband dial-up Internet users. Figure 3 is a telephone line LED lamp circuit schematics, telephone line DC voltage 36V or 48V via 10k limiting resistor by four diode (or rectifier bridge) as polar transform applied to the LED, when the telephone feed voltage to 36V, the measured operating current of about 1.2mA, the brightness is low, the current limiting resistor into 5.6k current work promoted 2.1mA: brightness slightly increase.

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