Use Arduino(5V) to switch a 3.3V

Question

I have a HDMI switch that I want to control with an Arduino. It's working by pressing a button to change input signal. The button is NC(Normally Close). By pressing the button you break the 3.3V going throw it.

I want so when you send 5V from Arduino you to break the switch of the 3.3V. What component is best for doing this? Will a transistor work? Doesn't it mean I need to apply 5V all the time except when breaking the switch.(Don't want that)

• Is there any MOSFET that will work?
• I have been looking at CMOS 4066?, is that a good IC for the job?
• Or is there any relay IC that work?

Answer 1

I'd recommend a bistable mechanical relay. Advantages:

• Electrically isolate your Arduino and HDMI switch
• Holds either state without power (especially useful for noise suppression)
• No voltage drop across closed contacts; exactly replicates electrical properties of the switch you'd replace

A quick search revealed a candidate (PB1618-ND) with bistable operation perfect for an Arduino; a 5V-rated coil draw of 12 mA. The contacts are rated for 1A @ 125VDC, which should be plenty for a little switch.

• Ehel: thank you vary much for the help. That component is a bit big an would not fit within the case of the switch. I did try 2 component together.A CMOS 4066 and a 36-110 relay switch. I have just test it with a LED yet but the function work fine. Or can the CMOS 4066 have any effect on the 3.3V?
• Jay J: A quick peek at a CMOS4066 datasheet seems to indicate that in the 'on' state, it acts as a resistor. So you may run into trouble if this conflicts with a pullup/pulldown resistor built into your HDMI switch.