Charger...

Greetings, O venerable All! To increase traffic. :) ================== begin of file "ZarqdBat.C" ================== A simple source of *stable* current for charging batteries. =============================================================================== *Very* well “holds” the rated current throughout charging process (with a working battery, of course). Suitable for charging any batteries with maximum capacity do not more than 15a/h. Initially it was assembled for charging "finger" (size 'AA') Ni-Cd batteries with a capacity of 500mAh (0.5a/h) and showed great excellent results compared to Chinese “adapters”, and also "industrial" devices from the Ethnic technical thoughts. The nominal charging current is equal to the battery capacity divided by seven. (Izap.nom. = battery capacity/10) Charging time: - for Ni-Cd (nickel-cadmium) = 14 hours. - for Pb (lead) = 10 hours. Scheme: ====== C1 0.1uF (ceramic!) ┌───────┐ ┌───┤├────┐ Uin. │LM317 │ │ R1 │ + / - +Uin>──────o───┤KPEH12A├───o───███───o───(mA)──<<─┐ │ │ │Uout. │ / │ │+ └───┬───┘ │ * PA1 │+ ─┴─ │Preg. │ ──┴── ─┬─ └─────────────────┘ B1 ─┬─│ 100uF │- ▀▀▀25V │ ┌──<<─┘ Iout.stabil.= 1.2/R1 │ (Iout.stabil - in Amperes, R1 - in Ohms) ▀▀▀ * Milliamp meter PA1 is needed only for test charge control no current. 0.8 Om >= R1 <= 120 Ohm That is the microcircuit is capable of delivering a stable current in the range from 10mA to 1.5A. (at 10mA the current does not “hold” very confidently). Depending on the value of the output current, R1 must be set with the corresponding permissible power dissipation: P(R1) = 1.2 * Iout.stabil. The input voltage is calculated based on the rated voltage charging a fully charged battery and then using adding three volts for normal operation of the microcircuit: Uin = U(B1nom.)+3V Calculation example: =============== You need to charge two Ni-Cd batteries with rated capacity each 500mAh (rated voltage of each 1.25V). Turn on tea them sequentially. Voltage supplied to the charger the device (Uin) will be 6V (I have 15V :). The charge current is 50mA (for 14 hours), R1 = 24 Om. That's it, let's charge... :) I wanted to I would like to note that it is necessary to *exactly* maintain the charging time (14 hours in our case)! Undercharge or overcharge - not up to let's go! !!! At a current >60mA, the microcircuit must be installed on a radiator! MS PIN assignment:============== ┌───────┐ │ O │<- Uout ├───────┤ │LM317 │ │KPEH12A│ └─┬─┬─┬─┘ │ │ │ Reg.│ │ │Uin. Uout. KREH12A = KP142EH12A (KP142EH12B do not use!) LM317 = Bourgeois original of “our” KP142EH12A . ================== end of file "ZarqdBat.C" ================== Best regards, Felix. [I.ZX]