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I'm trying to connect an old radio to a powerbank. I used the the wires from the 6v battery holder and connected them to a usb cable. Now, when I insert the usb cable into a powerbank, the radio will work fine. However, it soon stops working, most of the time after a couple of minutes. I would like to solve this problem and not re-insert the cable every couple of minutes.

When I insert the usb cable into a usb cellphone charger that is connected to the grid, the radio keeps working without a problem. Why does my powerbank 'refuse' to give elektricity to the radio the same way the grid does?

I've tried placing a 470uF capacitor between the + and - . This seems to have no effect.

I measured the amps that the radio draws from the power bank. It seems fluctuate between 43 mA and 150 mA max.

All help is greatly appreciated

Martijn

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I suspect that your radio is drawing too little current making the power bank think that there is no load and switching off the 5 V.

Possible solutions:

Use a different power bank that does not switch off

Draw more current, for example by connecting a 6V light bulb (bicycle light) in parallel with the 5 V.

Draw more current by switching on the cassette recorder function, you can try that now and see if it prevents switching off.

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  • \$\begingroup\$ I think you're right. Very good suggestions and I thank you for them: Unfortunately i've disabled the casessete recorder by accident. Also, I don't a lightbulb. Would it be possible to use a resistor of some kind? And where would I place it? \$\endgroup\$ Commented Jan 12, 2016 at 21:59
  • \$\begingroup\$ Resistor yes but watch the dissipation so that the resistor does not burn out ! Use: R = U^2/P , U = 5 V, P = max power resistor can dissipate. So for a standard 0.25W resistor: 5^2/0.25 = 100 So 100 ohms. So try one or more 100 ohms resistors (higher value is also OK) in parallel until the power bank does not power down anymore. You need to place all resistors in parallel with the 5 V from your power bank. \$\endgroup\$ Commented Jan 13, 2016 at 14:01

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