Hello, I would like to ask you for a simple circuit, that doesn't need an external power supply and works like this: if it recognise voltage on specified level (4-6V), it will Interrupt the connection in another circuit. When the voltage disappears, the other circuit will work again. So, when charging voltage in my circuit is present at some "sensor", it will disconnect one positive contact from battery on another circuit, which is powered from battery. This doesn't allow the circuit powered from battery to run, when the battery is charging.

 

Logic level (low-voltage) P-channel mosfets turn off when their gate goes high. That can be used to disconnect a battery from a charger. Diode logic can steer which circuit is working.

 

Thank you jpanhalt, but how can I Interrupt connection from working circuit? Can someone post schematic, to imagine how it Works? Thank everyone for the answer.

 

Can you be more explicit by what you mean to "interrupt connection working circuit"? Both of these approaches do that and are quite common"



In the above circuit, "VBATT is the rest of the circuit. It is isolated (removed) when the charger is attached. In the following version, the circuit is isolated from the battery while the battery charges, but battery power to the circuit resumes upon removal of the charger:



VBAT2 is the rest of the circuit.

The first used a P-Mosfet; the second uses steering diodes. You can also have combinations of the two and other arrangements.

 

Thank you, you helped me a lot. I made only circuit with MCP73831. Disconnected circuit is MAX16054, or is it part of the circuit for disconnecting?

 

The MAX16054 is a push on/push off switch with debouncing. As I said, VBAT2 goes to the rest of the circuit. The next component is an LDO regulator for 3V3 volts.

That battery charger is not an important part of the circuit from a switching standpoint. In fact, I probably wouldn't even recommend that device unless you are using a low-capacity battery.

The next step seems to be for you to read about steering diodes, mosfets, RDL (resistor diode logic) and so forth. Then post a draft diagram of what you plan to do.

 

This are 3 parts of the schematic, (attachment 1) translated to English, 1. Power supply, which converts 3,7V battery to 12V, 0,5A using MAX669 in non-bootstrapped operation, 2. Battery charger using MCP73831 and 3. is Battery level indicator using LM339N. The Main circuit (attachment 2) is in the picture 5 - tube am receiver - audion. Picture 4 will be automatic control of shutting down audion, while charging. So it will work like this: when voltage of 5V will be present in points 5V/1A in the picture 2 - charger, the circuit Interrupter will disconnect positive (ground can be connected, that doesn't matter) from the battery, and MAX669 with battery level indicator will not be powered, while the voltage 5V will be at the input of the charger. As long as 5V will be appearing here, the circuit will be interrupting other circuit, as mentioned. I don't know much about working of the MOSFETs, I know a lot about vacuum tubes and historical electronic, so I have a little problem with this. I wanted to make this little receiver audion to receive MW, here in Slovakia you can actually get some stations tuned on MW.