Hello why not just use 2 pins on a 5v mcu, if you need it to be small maybe attiny85?Just have the pins set to input and when you need to push the buttons just change it to output and it will ground the pin, and then just change back to input to release the button.Just a thought.Best of luck!
These relays basically set to GND and output for the intercom controller, that is normally at 5v. The currect is therefore very low.
The output to low just grounds the pin, so the voltage differential is almost 0, you have to worry about the current your system draws and see if it's not too much.Just to be clear, aren't you confusing voltage and current? Being 5v doesn't imply the current is low.
I know that the current is very low because I read it in the intercom microchip datasheet. I know that current can be hi even with 5 volts.
Made some tests with the 4066, but the resistance in the output sometimes generates issues.
Ok, I just wanted to confirm if that "Therefore" was about the 5v or about the intercom.If I'm not mistaken, from the datasheet, the 4066 supports only 10ma.It's good to check the current anyway, just to be sure, but the Esp8266 can support up to 15ma.Come to think about it, you'll face the exact same problem with the Esp8266, but the internal resistance is lower (about 50 ohms) instead of the 180 ohms of the 4066Why isn't the optocoupler a good idea again? It is basically a switch, has about the same internal resistance, and you protect your Esp8266.
5V DC or AC?What current?Often you can replace simple buttons by optocouplers - safe (no electrical contract), and will work assuming the current through those buttons is no more than a few mA. If more than that, it's becoming harder - your comment on the use of the 4066 suggests this actually may be the case, but details are missing.The moment you connect your project to those buttons directly you also need to know the actual voltage level of the poles of the buttons. With that I don't mean the voltage difference when off, but whether the low end of the button is at ground potential, and whether the low sides of both buttons are indeed connected, etc.
Note that when referring to a "4066", we must be talking about a 74HC4066, not a CD4066 which has much higher "on" resistance.If pulling to ground, just use a transistor. A bipolar would do, a logic level FET is better and nowadays, almost as cheap.If you really want proper advice, you need to provide the circuit relating to the intercom device and the information you have on its microcontroller.
Note that all electronic switches (like the 74HC4066) can only switch things within their own supply range.If the chip is powered with 3.3volt, then the load must also be <3.3volt and >ground.Can't switch something 'floating' (no ground shared with the chip).If you want to switch something not galvanically connected, then use an opto coupler (or opto fet).Leo..
An optocoupler is also of course an option. Is just that is requieres double cabling and it might be more complicated to find (max. current output for 8266 is 12mA) ... any suggestions? thanx!
I am using a Esp8266 that has 3,3V in the output...
The 74HC4066 is connected to a 5v source.
What I essentially need is a relay inside of a IC that would be able to have very low "on" resistance, accepts maximum 14 micro amps and able to switch the status with 3,3 volts.