There are 4 circuits, as follows.
1. The universal battery charger using Lm317
Here comes very simple idea is the universal battery charger circuit. When, an input power is applied to the circuit. The SCR1 (Silicon controlled rectifier) turn off, then not has a bias current path to ground.
2. 6V or 12V lead acid battery charger using LM317
This circuit be lead acid battery charger again interesting circuit, Because it can charger get both of 12V sizes and 6V. By change with switch only and this circuit charging with current about 1Amp. When see the circuit you will think us uses integrated number highly popular circuit be LM317K again. By when you Close SW1 make can charger battery 6V get. Which have voltage come out about 7 Volt. But enough Open SW1 as a result use charging battery 12 V get. Which give volt come out about 14Volt supposing that you use battery 6V 10Ah take time charging current 10 long ago hour. The diode D3 and D4 help protect voltage turn back from battery get. The detail is other see in the circuit.
3. 12V lead acid battery charger by LM317K
Today a close friend visits tell want Dry cell lead acid battery charger circuit 12V 7.5hA sizes. In model to are simple and economize with. I then advise this circuit try build see. By use the integrated circuit voltage regulator the number is highly popular be , LM317K. This circuit has the principle is simple be heal level voltage be stable 13.5 Volt. Because battery must use voltage tall more then charger get follow want.
4. Automatic Charger and Full charged indicator using LM317K-TL431
This is circuit Automatic Charger and Full charged indicator. For 24V batteries it can charger with current be stable about 1.5A and have voltage output 27Volt with integrated number circuit LM317K. When the battery has had full already , as a result will cut the work. There is a tube LED show the work with use integrated number circuit LT431 perform check the level , voltage battery and systematically protect short circuit with IC LM317. Unless D2 perform protect wasp a pole battery wrong as well. The IC1 should hold heat sink with. The detail is other , see in the circuit.