Flip-Flop in analog?

[headshrink]

Can you easily make a set/reset type Flip-Flop circuit in analog using basic radio shack parts.

If so, what is the NEWBIE version? What do I need and how do I put it together?

I have been scouring the net for 2 days and cannot find an answer.

[Anemone]

[moved]

Kevin

[headshrink]

Sorry about that - I inteded to put it in this forum. I was in a hurry, which one did you find it in?

[xrunner1234]

What are you trying to do?

Just a quick google search.. http://www.allaboutcircuits.com/vol_6/chpt_7/5.html

[headshrink]

This is the project:
http://archive.reefcentral.com/forum...hreadid=731947

In the first part of my post I am not vary clear on what I want, but I have much more clarity toward the bottom.

It is for a "Doctors/Nurse Call Light." When a patient arrives they would hit a button with my name next to it and a light turns on in my office. I wanted to use a momentary button instead of one that clicks open and closed. I knew I had to use a latching relay to do this. The reset button is to be located in my office BUT, I also want the trigger button to reset the light should a patient hit the wrong button. I don't want to put separate trigger and reset buttons on the panel. I know I can just use 3-ways, I just wanted the momentary type button and fun with relays. From my internet homework it looked like what I wanted was a flip-flip circuit. All the stuff I found uses solid-state stuff.... I would like to only use mechanical relays if possible.... solid-state is still above my head.

[BruiseAndy]

How many buttons for trigger? Let me know and i'll see if i can whip you up a fabulous mspaint schematic. Might be awhile due to the weekend.

[headshrink]

Just one trigger per office. I don't mind if the reset button in my office also triggers, primarily I just want the waitingroom trigger to also reset. (There are 2 offices so I will just make it twice).

Thanks

[Homebrew]

Originally posted by BruiseAndy
How many buttons for trigger? Let me know and i'll see if i can whip you up a fabulous mspaint schematic. Might be awhile due to the weekend.

Cool... post it if you don't mind. I haven't decided (nor thought too much about it yet), but I have to design (or buy) a simple call light system for my wife's new office that we are getting ready to build. I was thinking of using DC LED push button lights, but hadn't thought about the triggering mechs yet. I did design how I wanted it to function though. So I'll just be tagging along as headshrink works through his configuration.

[Donw]

A lathing relay and 2 momentary dpdt switches should do the trick. 12v applied to the relay turns it on. Applying 12v a second time with the polarity reversed will turn it off.

Don

[Homebrew]

Not to hijack, but I think this question is also along the lines of what headshrink is looking for (I guess I need to look back on the other thread too), but what if you want the same switches to turn on and off the lights? What would reverse the polarity... would something instead of or in addition to a latching relay be needed? I have good tools to put the thing together, but just need to find an appropriate circuit diagram.

[Homebrew]

Yup... went and looked back at the updated posts on headshrink's original thread and we want to basically do the same thing... use the momentary push button lights to turn them on and off. Well... for me it will be a project after the holidays.

Headshrink - as I said, I didn't get into the circuitry yet, but here is the function of what I was looking to do in my wife's 2 doc practice. A little more complicated than what you described, but really the same basic functionality:

[headshrink]

Wow... that is a lot more complicated than mine.

[headshrink]

^

[BeanAnimal]

shrinky.... looks like you are in pretty good hands... I am still a bit busy to whip up a handy dandy schematic for ya....

Xrunner and donw and bruise are fully capable of anything (or more) than I am.

Bean

[headshrink]

Originally posted by Donw
A lathing relay and 2 momentary dpdt switches should do the trick. 12v applied to the relay turns it on. Applying 12v a second time with the polarity reversed will turn it off.

Don

Could you explain this with a simple sketch.... I am sooo close to getting it.

[stugray]

Sorry to pipe up on this thread ( I got in trouble on the other one ).

What is your budget? Are you really trying to save as much money as possible ( which results in maximum engineering cost ), or are you trying to make it as simple as possible just for DIY bonus points?.

In my experience, keeping the build costs down is only useful for mass production ( or DIY points ). There are things on the market that can do what you ask for out of the box for $200 ( Square-D PLC ). If you really want to build it yourself, then the time & energy expended MAY save you some money, but no guarantees.

For a one-time-build, just use COTS ( commercial off the shelf ). That keeps the NRE ( non-recurring-engineering ).

( Here's one on Ebay for ~$10: Melsec FX-32MT PLC Programmable Logic Controller ). Yes it will cost some time & effort to figure out how to use it, but the first time I used one, I got it figured out on a cell phone & 20 minutes with the help desk & manual.

It's the cost of the engineers that drive up the costs of custom builds. These PLC companies figured that out, and provide these things dirt cheap to get the job done.

Stu

[Donw]

Two DPDT momentary swithces one in each room. These get a 12v + and - both polls are NO. A single pole latching relay. Each switch is wired to the relay coil but with reverse polarity (dont push both switches at the same time). Pushing one button sends + and -, pushing the other sends - and +. The 12v leds (lights) are connected to the relay outputs. Give me a few I'm sure I can make it even easier.

Hope this helps
Don

[55chadman]

here is the simplest idea!!!!

got to home depot or lowes buy a few wireless door bells set them to different frequencies and put them on a board with the names of dr's and put the ringers in the offices

if the ringers are to loud just hack into it and wire up a led or lowvoltage lightbulb or put a relay on it and wire up a 120 volt lamp to it ---- for the relay look on floatswitches.net website for the relays --- its just like wireing the low voltage float switches --- the trigger is the speaker and the output is 120 volt to the lamp

im guuessing only 100 to 150 bucks worth of materials even cheaper if you want to ebay it !!!!

hth

chad

[Donw]

Not sure about that, but if you want very simple. Just wire up 12v lamps to a shared power supply. Buy 2 x10 remotes and a appliance module and your done.

Don

[headshrink]

Originally posted by Donw
Two DPDT momentary swithces one in each room. These get a 12v + and - both polls are NO. A single pole latching relay. Each switch is wired to the relay coil but with reverse polarity (dont push both switches at the same time). Pushing one button sends + and -, pushing the other sends - and +. The 12v leds (lights) are connected to the relay outputs. Give me a few I'm sure I can make it even easier.

Hope this helps
Don

This sounds like the holy grail.
I am trying to draw this out but am struggling. Could someone please post a sketch? please, please, please.....

[headshrink]

I am so close to figuring it out myself. I can't figure out what a NO DPDT momentary switch would look like. All the schematics of DPDT switches I find don't look like they could be momentary.... I'm talking about the schematic view.
I find them as toggle switches (3 positions), but not buttons (1 resting position)

[Donw]

http://wolfstone.halloweenhost.com/T..._Switches.html

This should show you how they work DPDT is about half way down. I havent had time to draw any pictures.

Don

[headshrink]

Is this the right switch?
http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA%3AIT&rd=1

[headshrink]

I think were I am confused is how you can have DPDT in a momentary push-button and remain NO ... a SPDT makes since, but it looks to me that when you push it you will get rev polarity quickly then return to normal. It appears to me that it's resting point would be NC to one pole and NO to the opposite and pushing the button would reverse poles while finger is on it.... but to release you are NC again.
Am I over thinking this?

[Donw]

http://www.radioshack.com/sm-dpdt-20...i-2062530.html

Don