| Electronics > Beginners |
| Big current draw in simple timer circuit. |
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| MarkusAnd:
The LEDs I use are the "normal" low powered LEDs you can buy as an assortment. According to the product description, they should be fed 20mA. |
| Zero999:
The transistor's gain is probably much higher than specified on the data sheet. Never rely on the hfe of a transistor to limit the current to an LED. You need a series resistor. The current surge due to the capacitor is unavoidable. There are better ways of implementating a timer, such as the classic NE555. |
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