Good to all!
Once I wrote a shameful opus:
Charging for a screwdriver from what was
The people rightly called:
“From the description it is difficult to understand anything, some fragmentary set of words and photographs of a carelessly designed product.”
I completely agree!!!
I decided to redo and describe in detail a new home-made charger for a 14.4 Volt, 1.3 Ah battery screwdriver, with discharge and charge, or an indoor switchgear.
Charge instead of a transformer with a rectifier, power supply from a Canon AC Adapter k30245 printer.
A discharged battery, (in my case, 10 volts), will be charged by a charger with an EMF of 15 - 17 V, depending on the need for charging speed, without additional current / voltage limiters, i.e. - direct "charge constant voltage"
Full charge with a large current (more than 2.5 A) in 2.5-3 hours. And up to 50% in 15 minutes.
Forced battery discharge.
Why forced discharge?
It is needed so that the battery capacity does not decrease, that is, to eliminate the effect of "memory".
The discharge will occur due to the power supply and cooler.
Discharge limiter according to the scheme:
Adjusting load shedding at 10 volts, less scary ...
Battery charge.
We disassemble the printer, dismantle the power supply.
I put the voltage output adjustment from 24 volts to 7 volts.
By replacing the resistor R51 with an alternating one.
I will assemble the ZRU on the ATX case.
Battery discharge
Assembled according to the scheme of mounted installation, for the production of tests. The tests were successful, the protection disconnects the load at 10 volts.
Then transferred to the board:
Next, I complete everything in the case:
On the old switchgear there was a battery charge limiter, this time decided to abandon it in favor of a voltmeter.
When I charge, I set 15 volts (battery 14.4 volts), I won’t take on more batteries for any period of time, I set 16-17 volts for faster charging.
Additionally installed a USB mother through L7805. Smartphone on the way to charge, etc.
The cooler is connected via L7812.
On the back wall of the housing brought an output of adjustable voltage, it suddenly comes in handy:
Now about the work of the indoor switchgear.
I put the discharged battery into the socket when the power is off.I set the switches to the "Discharge" position
The final discharge of the battery to 10 volts (5-10 minutes) occurs, depending on the discharge.
Further, the battery has thinned out, I switch the keys to the “Charge” position and turn on the power of the power supply.
The charge has gone.
The battery does not heat up during the entire charging cycle for 8 hours. Why 8 hours? The tests however ...
While the flight is normal, operation will show!
All to everyone !!!
