![auto turn auto turn](https://images.squarespace-cdn.com/content/v1/5d43bb05bbc6e50001866250/1609739386896-XRX939KZ1D28L1J8FD5F/set+ps5+dualsense+controller+to+auto+turn+off+by+itself.png)
As the voltage per cell increases beyond 1.3V, the voltage drop across resistor R4 starts decreasing. Pushing switch S1 latches relay RL1 and the battery cells start charging. Diode D6 connected between the output of IC1 and battery limits the output voltage to about 6.7V, which is used for charging the battery. Preset VR1 is used for adjusting the bias voltage. In the charging section, regulator IC1 is biased to give about 7.35V. Now even if the push button is released, mains is still available to the primary of the transformer through its normally open (N/O) contacts.Īuto turn-off battery charger circuit Auto Turn-off Battery Charger Circuit This in turn, turns transistor T1 ‘on’ to energize relay RL1. When a current of over 65 mA flows through the 12V line, it causes a voltage drop of about 650 mV across resistor R4 to drive transistor T3 and cut off transistor T2.
![auto turn auto turn](https://az417944.vo.msecnd.net/equipment/snowblower/images/articles/ariens-drive-differential.jpg)
Resistor R4 (10-ohm, 0.5W) is connected between the emitter and base of transistor T3. Transistor T1 is driven by pnp transistor T2, which, in turn, is driven by pnp transistor T3. Relay RL1 is connected to the collector of transistor T1.
#Auto turn driver
The relay driver section uses pnp transistors T1, T2 and T3 (each BC558) to energize electromagnetic relay RL1. When you press switch S1 momentarily, the charger starts operating and the power-on LED1 glows to indicate that the charger is ‘on.’ Regulator IC LM317 (IC1) provides the required 12V DC charging voltage. In the AC-to-DC converter section, transformer X1 steps down mains 230V AC to 9V AC at 750 mA, which is rectified by a full-wave rectifier comprising diodes D1 through D4 and filtered by capacitor C1. The circuit is simple and can be divided into AC-to-DC converter, relay driver and charging sections.
![auto turn auto turn](https://production-resources.bricsys.com/static/common/applications/attachments/759/1238/big_global.jpg)
It can be used to charge partially discharged cells as well. This auto turn-off battery charger for series-connected 4-cell AA batteries automatically disconnects from mains to stop charging when the batteries are fully charged.