12V and 9V Q.C. Trigger Circuit
by eletronicasempcb in Circuits > USB
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12V and 9V Q.C. Trigger Circuit
Not everyone has those cheap USB trigger boards available, so, with that in mind, I made a simple circuit with very few components that is capable of triggering 12V or 9V using Quick Charger 2.0 protocol (the charge must have support!).
Supplies
Components used:
12V circuit:
- 1x NPN Transistor (almost any one will do, I used the BC337);
- 1x LED (must have a drop voltage >2V, so white, blue, or green LEDs must suffice);
- 2x 10K Ohms resistors;
- 1x 100k Ohms resistor;
- 1x diode (0.6V drop, a simplediode like 1N4007 or 1N4148);
- 1x electrolytic capacitor 10 to 100uF (higher capacitance will take longer to trigger, but to little and it will not trigger).
9V circuit:
- 1x NPN Transistor (almost any one will do, I used the BC337);
- 1x LED (must have a drop voltage >2V, so white, blue, or green LEDs must suffice);
- 3x 10K Ohms resistors;
- 1x 100k Ohms resistor;
- 1x diode (0.6V drop, a simplediode like 1N4007 or 1N4148);
- 1x electrolytic capacitor 10 to 100uF.
That's all :)
How It Works?
Based on this Texas Instruments PDF about Quick Charge protocol, it basically uses a simple delay through charging a capacitor and turning the transistor on. The D- pin needs a minimum delay to trigger other voltages. While for 12V both D+ and D- needs around 0,6V, I used a simple diode to achieve this. On the other hand, for 9V it needs more than 2V on the D+ line, so I used a white LED (with a voltage drop of around 2,5V) to achieve this. The capacitor charge slowly and after a few seconds it sends 0,6V to D-, triggering it.