This 3A charger was originally designed to work with small batteries like those used in motorcycles. In principle it
can be used to charge car batteries also but will take a lot longer.
The charger below charges a battery with a constant current to 14.1 volt. When this level is reached, the current
charge drops automatically to a safer level (13.6V) and keeps charging at this slower rate untill the LED lights up
indicating a fully charged battery. This project looks very much alike with the Gel cell II charger elsewhere posted
in the 'Circuits' section. The difference is the IC, namely a LM1458 instead of a LM301A. Nice job Jan!
Click here to download the full size of the above Circuit.
The LM350 is an adjustable
voltage regulator and keeps the voltage between points C and B at 1.25 Volt. By adding a 1K resistor between point B and
gnd (-) you can, as it were, lift up the output voltage. To accurately control the output voltage we add to this
resistor, in series, a 2K adjustable 10-turn potentiometer. As soon as a battery is connected a current flow occurs,
controlled by the right halve of the LM1458. The current through the 0.1 ohm resistor causes a voltage drop. This drop
is compared with the voltage on the walker of 100-ohm pot. The moment this drop is greater than the one adjusted with the
potmeter will cause the output of the LM1458 IC to go low and a small current starts to flow thru the diode and this in
effect will reduce the current through the series resistors 1K + 2Kpot. The current is hereby stabilized. The point between C and B is devided by three resistors; 2.2 ohm, 100 ohm pot, and the 150 ohm. 2.2 ohm and the 100 ohm
potmeter are connected to the non-inverting input (+) of the LM1458 IC. The inverting input (-) is connected to the 0.1 ohm
wire-wound resistor in series with the output. As long as the voltage drop, caused by the current-flow over this resistor
is greater than the voltage drop over the 2.2 ohm resistor the output of the LM1458 will stay high and in turn block
the BC558 transistor. But as soon as the charge current falls below a...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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