I am putting in a system on a boat where the DC is disconnected on the pannel when not in use. The stereo may sit idle for a month at a time. So if I precharge the capicator and put it in the system, won't I have to precharge it before every use if the power is disconcected between uses?
I did not know there were soft start capicators out there when I bought mine, otherwise I would have bought that.
thanks
I did not know there were soft start capicators out there when I bought mine, otherwise I would have bought that.
thanks
soft start capacitors
A large capacitor draws a large amount of power and will arc or cause other damage with the large inrush of current.
A soft start capacitor has a series of resistors and a relay configured so that the power to the capacitor is not connected by the relay until a certain voltage has been achieved.
A large capacitor draws a large amount of power and will arc or cause other damage with the large inrush of current.
A soft start capacitor has a series of resistors and a relay configured so that the power to the capacitor is not connected by the relay until a certain voltage has been achieved.
It must be a huge capacitor that you're using. Say if you're using a 1Farad cap, and off resistance of 1 million ohms, then your looking at a tau of 11.6 days to drop to 1/3 of the battery voltage.
So if it's sitting disconnected for a month it will be pretty much discharged. You could use a soft start circuit. Although I've never made one, i imagine putting a resistor between the battery and capacitor and having a relay bypass the resistor when the capacitor is charged would work.
Try searching for a slow start circuit.
So if it's sitting disconnected for a month it will be pretty much discharged. You could use a soft start circuit. Although I've never made one, i imagine putting a resistor between the battery and capacitor and having a relay bypass the resistor when the capacitor is charged would work.
Try searching for a slow start circuit.
Here's a circuit I designed for your soft-start:
This will take care of your inrush current. The comparator (LM339) turns on the relay after the capacitor has charged up to the battery voltage, minus a 0.6V diode drop.
The circuit will stay latched (on) until you disconnect the battery and drain the 1F cap.
You can use an Op-Amp in place of the LM339 if you prefer. You can also use a 10 ohm, 10W resistor in place of the light bulb.
This will take care of your inrush current. The comparator (LM339) turns on the relay after the capacitor has charged up to the battery voltage, minus a 0.6V diode drop.
The circuit will stay latched (on) until you disconnect the battery and drain the 1F cap.
You can use an Op-Amp in place of the LM339 if you prefer. You can also use a 10 ohm, 10W resistor in place of the light bulb.
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