The circuit in the figure derives its power from a USB port and produces 5 and 3.3V supply rails for portable devices, such as digital cameras, MP3 players, and PDAs. The circuit allows the port to maintain communications while, for example, charging a lithium-ion battery. IC2 boosts the battery voltage, VBATT, to 5V, and IC3 [...]
Led Flasher with IC 555 Circuit A dual tandem flashing light circuit powered by a 9 volt battery, This circuit is powered by a 9 volt battery, suitable for warning lights on a tall structure. (Personally, I can’t recommend you buy anything but the Rollins Railroad Designs kit; for $4.00 you can’t go wrong. The [...]
The original CK217 was an improvement on the CK200 FM Transmitter. This new FM Transmitter can transmit over 900 feet in the open depending on aerial used. The tank oscillator coil is built into the circuit board, and has been tinkered with to give the best distance and stability for it’s size. The battery supply [...]
Low cost solution for charging of both NiCd and NiMh batteries Here is the circuit diagram of a low cost universal charger for NiCD – NiMH batteries. This circuit is Ideal for car use. It has ability to transform a mains adapter in to a charger . This one can be used to charge cellular [...]
Stops charging when battery is full charged, Portable unit Charging of the mobile phone, cellphone battery is a big problem while traveling as power supply source is not generally accessible. If you keep your cellphone switched on continuously, its battery will go flat within five to six hours, making the cellphone useless.A fully charged battery [...]
Monitors battery voltage, Three-LED Display Connecting this circuit to the battery of your vehicle, you will always know at a glance the approximate voltage available. An indication of battery voltage is useful to the motorist for monitoring the battery’s capacity to deliver current, and as a check on the efficiency of the dynamo or alternator. [...]
This electronic circuit is an alarm circuit for low battery condition. It provides an audible and visual low voltage warning for 12V battery powered devices. When the battery voltage is above the set point (typically 11V), the circuit is idle. If the battery voltage should fall below the set point, the LED will light and [...]
