Author Topic: SPDT electronic switching circuit help  (Read 1625 times)

armdnrdy

SPDT electronic switching circuit help
« on: August 28, 2012, 03:20:58 PM »
I'm working on a circuit that needs to be switched by a SPDT switch. This switching needs to occur when a constant voltage of 7vdc appears at the output of an IC.

I've looked into the standard 4013/4053 switching as well as 4016 switching, but if I'm correct, they all need a pulse (momentary switch) to change states. I also looked into a monostable multivibrator circuit to supply a pulse to a 4013, but that circuit needs a momentary switch as well.

What I need is the equivalent of a relay, where a constant voltage activates a coil which in turn changes the state of the contacts.

Does anyone have any suggestion, or am I stuck using a relay?
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

slacker

Re: Re: SPDT electronic switching circuit help
« Reply #1 on: August 28, 2012, 04:02:14 PM »
4016s and 4053s don't need a momentary switch, they are in one state when a high voltage is sent to the control pin and the other state when the control pin is low. Bypass designs with them that use a momentary switch normally use some sort of flipflop to make each press of the switch change from high to low. 7 volts from your IC might be enough to switch them, assuming a 9 volt supply, if not you'll need a level shifter or some other way to connect them.

armdnrdy

Re: SPDT electronic switching circuit help
« Reply #2 on: August 28, 2012, 10:13:38 PM »
Hey Slacker,

Good to know, I think that the term "Digital control inputs" (CD4053) and "Binary control inputs" (CD4051 & 4052) as described in the data sheet led to a bit of confusion.

Also, upon further review of the drawing labeled "Using the CD4013 to control the CD4053" on RG's site, I noticed that the output Q of the 4013 was powering a status indicator via a NPN buffer. That would be hard to accomplish if there was no power between the 4013 Q output and the 4053 control input!
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)