Mutchus

  The below circuit is a Simple Lithium Ion Charger 2 Cell Circuit Diagram. This circuit was build to charge a couple series Lithium cells (3.6 volts each, 1 Amp Hour capacity) installed in a portable transistor radio. The charger operates by supplying a short current pulse through a series resistor and then monitoring the battery voltage to determine if another pulse is required. The current can be adjusted by changing the series resistor or adjusting the input voltage. When the battery is low, the current pulses are spaced close together so that a somewhat constant current is present. As the batteries reach full charge, the pulses are spaced farther apart and the full charge condition is indicated by the LED blinking at a slower rate. Simple Lithium Ion Charger 2 Cell Circuit Diagram A TL431 , band gap voltage reference (2.5 volts) is used on pin 6 of the comparator so that the comparator output will switch low, triggering the 555 timer when the voltage at pin 7 is less than 2....

A sensitive detector for static electricity based around a single Field Effect Transistor It can also be used to detect the presence of negative ions, or test a negative ion generator. This circuit utilizes the extra high input impedance of a FET, and also demonstrates the gate terminals sensitivity to changes in voltage. The gate terminal here is left open circuit,connected only to the "probe". The probe is just a few inches of bare copper wire. With no fixed DC biasing, the gate terminal will respond to micro changes in voltage. This causes a current change in the drain circuit and the meter will indicate a charge or "field strength". Static Detector Negative Ion Detector Circuit diagram It is important not to make this circuit on veroboard or PCB material as this will reduce the effective gate impedance. Instead use an "open" construction technique soldering each component together. The probe should not be touched directly and is best insulated in a pla...