DIY: AC Remote Touch Upgrade

How to use the TTP223 to modify an Air conditioner remote control’s touch light?

The TTP223/TTP223N TonTouch™ is a touch key detection IC that provides a single touch key. The touch detection IC is designed to replace traditional button keys with keys of varying areas. Low power consumption and a wide operating voltage are characteristics of touch keys in both DC and AC applications.

However, the TTP223 is overly sensitive. When placed on a wooden table, the touch light can turn on by itself. Even if you try to touch it, the light will come on before you even touch the board. The sensitivity can be adjusted with an external capacitor (0-50pF), which is the only capacitor on the board.

First, install it in the air conditioner remote control. The final connection method used is shown in Figure 2. The touch panel is glued inside the remote control with hot melt adhesive and can sense touch through the outer casing.

The power is directly drawn from the battery.

If the LED light is turned on for too short a time to generate heat and then turn off, it can work without a current-limiting resistor. However, you can add a voltage regulator diode across the battery.

After installing it into the air conditioner remote control, there were no sensitivity issues.

First, try the initial connection method. If you find it ineffective or think the transistor is unnecessary, you can directly use the following connection method.

This connection method is simple and practical.

The actual effect at night is quite good.