Does anybody have a simple anti-restart schematic, usable in conjunction with a 220V AC universal motor? Thank you.

 

Describe with a little more detail!
What reason for non-re-start?

 

You want to know what the anti-restart is? Imagine this: you have a power tool. You plug it in power outlet and you turn the start switch on. Everything is good, the tool starts as expected. Then, for whatever reasons, there is a power outage. You let the tool down with the switch still turned on and go for a break. Then out of blue the power goes back on. Without an anti-restart circuit your power tool would restart right away, unattended, possibly with hazardous consequences. In other words, an anti-restart circuit would prevent a system to start if at a time the system is connected to a power source the start switch is on the ON position.

 

You could use a relay configured as a latch (below) with ON and OFF buttons:
The top button turns it on, latching the relay, and the bottom button turns it off.
If the power fails, the relay will automatically unlatch since it has no power to keep it latched.

Of course you would use a relay with a 220Vac coil.

 

Thank you, crutschow, no doubt that design would work but I was thinking more like to a single switch design. Indeed, this is the problem with most of the anti-restart circuits. Most of them rely on relays, which is not intrinsically bad, but they tend to heat-up over long periods of time in idle mode.

 

As per Crutschow circuit, the standard Stop/start circuit been used for decades.
Ignore the OL contact

 

but they tend to heat-up over long periods of time in idle mode.

That is mainly pertinent for AC coils, use a small bridge and a DC coil relay!!

 

Thank you MaxHeadRoom, but let's not divert the my initial question. To make it clear, a two switches solutions, one for start and one for stop, is not an anti-restart circuit, as it defies the purpose.

 

Thank you MaxHeadRoom, but let's not divert the my initial question. To make it clear, a two switches solutions, one for start and one for stop, is not an anti-restart circuit, as it defies the purpose.

??You lose power to the relay, it doesn't automatically pick up on power return??
Its the same circuit as post #4?

 

but they tend to heat-up over long periods of time in idle mode.

Not if they are well design industrial relays.

one for start and one for stop, is not an anti-restart circuit, as it defies the purpose.

In what way?
It keeps the device from restarting if the power is lost, which is what you wanted.

I don't offhand see a simple way to do it with one switch or without a relay.

 

I have a relay flip-flop circuit that uses two relays and one PB. Push-on push-off, Power off, resets the flip flop to off.

 

??You lose power to the relay, it doesn't automatically pick up on power return??

That is the right question. When you will find a way prevent the rely to reengage when, at power up, a switch, somewhere in the circuit is turned on, you would be half way. The second half is how to make the rely still stay on, if the same switch turns on AFTER the relay engaged.

 

Sorry guys, I thought it would be a simple question. Basically, there is no power tool, from angle grinder to name it, made in the last 5 years or so that is not equipped with such a simple circuit.

 

Sorry guys, I thought it would be a simple question. Basically, there is no power tool, from angle grinder to name it, made in the last 5 years or so that is not equipped with such a simple circuit.

NOT in my wide electric hand tool inventory,?
These are N.A. or Europe origin, no Chinese versions.
None has a anti-start on feature if I leave the on switch ON??
Only the machine tools That posses a E-stop/Start relay!

 

there is no power tool, from angle grinder to name it, made in the last 5 years or so that is not equipped with such a simple circuit.

What I suggest then, is purchase one of the parts you claim is in any of the tools and do some reverse-engineering to see how it is put together!
Or use one of them for your DIY unit.

 

NOT in my wide electric hand tool inventory,?

Just out of curiosity, where are you from? Did you bother to do a quick google search on, let's say: angle grinder anti restart and see the pile of results? Metabo, Makita, Bosch, you name it, they all advertise products with this function. Ok, I'm not here to polemize side ways. If you don't have a definite answer to my question let me thank your time and let's move on.

 

I bow to your apparent superior knowledge on the subject, and as to where I come from is obviously as not as on a high a plane as one such as yourself.
Have a good Christmas!

 

Merry Christmas to you as well!

 

Merry Christmas to you as well!

If you can find the circuit you are looking for, I hope you let us know about it.

 

Sure thing. I actually have a working schematic that I'm playing with. It's surprisingly simple but it is relay based, and due to space constrains, the relay is rather undersized so it kind of heats up over time up to +50 degrees Celsius, that is not that bad, but it's not good either. I was hoping someone would come up with a better schematic, like triac based or something, I don't know.