Independent component QC2.0 fixed 12V automatic decoy device

This is a QC2.0 automatic decoder (no switch required), with a fixed decoy voltage of 12V, and a decoy 12V success indicator light. The cost of using independent components is extremely low.

It can deceive a large number of QC2.0 and QC3.0 (not PD heads), so that charging heads and power banks that support 12V output can output a stable 12V DC voltage for use by various devices.

The circuit refers to the designs of the great masters on the Internet. After a comprehensive analysis, the board test was successful and the use is very stable.

Related principles:

Four steps for QC2.0 output:

1. The power supply party short-circuit D+ and D-, which is required for the charging head or power bank;

2. After the power receiving party is inserted, 0.6V is output at D+, which is what the decoder needs to complete;

3. After the power supply detects this voltage for 1.25 seconds, it disconnects D- from D+ and pulls D- down to 0V;

4. After the power receiving party detects the drop of D-, it can obtain different voltages output by the power supply party by adding different levels to D+ and D- according to the required power supply voltage:

       D+ D- output voltage

       0.6 0 5V

       3.3 0.6 9V

       0.6 0.6 12V

       3.3 3.3 20V

Because this decoy only wants to obtain 12V, it outputs 0.6V on both D+ and D-. The 0.6V is provided by the junction voltage of 1N4148. An RC circuit composed of two 470K and a 10uF capacitor forms a delay circuit to control the N-channel field. The effect transistor 2N7002 is turned on with delay to realize the function of delaying supply to D- 0.6V;

The 12V deception success indicator light is composed of a 2K current limiting resistor, a 5.1V Zener diode and a LED in series. When the output is only 5V, the circuit does not conduct and the LED does not light up. When 12V is tricked out, the Zener diode On, the light-emitting diode emits light.

Circuit working simulation diagram:

The yellow line is VBUS, the blue line is the voltage of the positive electrode of C1, the red line is D+, and the green line is D-.

TYPEA interface (with deception success indicator light)

TYPEC interface (very small):