Why doesn’t the LED advertising light flash when connected to the power supply?
本文目录一览
- ⓵Two self-flashing LED lamp beads can work normally when connected in parallel on a 3V power supply, but if they are connected in parallel with a small electric motor, they will not flicker. What components should be connected to restore the function?
- ⓶All the LED lights are flashing. After changing the power supply, they are no longer on. Why are the lights still not on when the original power supply is connected?
- ⓷The motorcycle modified LED light wire is directly connected to the headlight wire, and the two LED lights will flash when the light is turned on. If the LED is directly connected to the battery, the flashing will stop
When the LED lamp beads are working, the current is very high Small, the internal resistance in the power supply produces a very small voltage drop under low current, so it can work normally.
After the motor is connected in parallel, the current in the motor branch is too large, causing the internal resistance voltage drop in the power supply to become larger, so the voltage applied to the LED is lower than 3V. The consequences of using electrical appliances when operating at conditions much lower than the rated voltage can be imagined.
You can confirm this by measuring the voltage across the LED with a multimeter while the motor is running.
The solution is to switch to a large-capacity power supply. The internal resistance of a large-capacity power supply is relatively small. For example, if your 3V power supply originally uses two 5# dry batteries, you can try using two 1# dry batteries instead. It is safer to find a DC adjustable regulated power supply that can output more than 5A (the kind in school laboratories). It will definitely succeed.
After the motor is connected in parallel, the current in the motor branch is too large, causing the internal resistance voltage drop in the power supply to become larger, so the voltage applied to the LED is lower than 3V. The consequences of using electrical appliances when operating at conditions much lower than the rated voltage can be imagined.
You can confirm this by measuring the voltage across the LED with a multimeter while the motor is running.
The solution is to switch to a large-capacity power supply. The internal resistance of a large-capacity power supply is relatively small. For example, if your 3V power supply originally uses two 5# dry batteries, you can try using two 1# dry batteries instead. It is safer to find a DC adjustable regulated power supply that can output more than 5A (the kind in school laboratories). It will definitely succeed.
First make sure that the new power supply has electrical output, that is, the lamp beads are burned out. Use a multimeter to measure them one by one and you will find out. It may be that the power supply is broken and the output current is unstable. The large current impacts the lamp beads, causing them to burn out.
The starting current is too low Well, remove the headlights or replace them with LED lights, or the voltage is no longer enough to be 9V.