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I have a joystick wired to a relay that spins a motor either one way or the other way.

The problem is that I need to enforce a small "dead-time" when the user pushes the joystick quickly from one side to the other to avoid stressing the gear to much.

What is the name for the component I am looking for? Its not strictly a time-delay relay since there should not always be a delay when the joystick is pushed, only when it is pushed from one activation state to the other.

Is it a standard component or will I need to design my own?

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As you already suspected: I am not aware of a standard component that will do it. I am afraid you have to make your own.

Of course a micro controller can do it, in discrete logic you mostly need to detect the change of direction. From that you can trigger a one shot which keeps the signal to zero for a while.

Detecting the change of direction depends on what your joysticks outputs as signal.

For the one shot look up mono stable multi vibrator, NE555 or 74xx121.

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You can not get what you want in a single relay. You will need two on-delay relays. It should be easy to find appropriate relays and design a relay circuit that will function in the way you have described.

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  • \$\begingroup\$ This answer was flagged as LQ because it is a one-line answer. It is the servers that flag stuff like this, even if the answer is correct. To avoid getting a LQ flag add some frivolous details that add maybe 2 more lines at least. \$\endgroup\$ – Sparky256 Jan 21 '18 at 21:36
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I don't know what you building, but in the older electric crane/wench controllers they just use two relays that the coil for the other relay goes through the normally closed when not energized contacts. This direction interlock circuit ensures protects fron short circuit conditions when swapping the volage around on a dc motor. Internally they have dynamic braking, but in your case, where you not current braking the motor, you could use an extra pair of relays they call delay on relays. you would put these after the controller relays (with direction interlock) and before the motor contractors.

I would also be aware of arcing at the motor contacts, and arc suppression should be looked at. Mostly, this is just at the main motor contacts where you would get a special relay that has a arc suppressor magnet in, or in some cases, gluing a small neodymium magnet on the case of the relay is sufficient enough to bend out the arc when it happens (if you can't get one small enough that has this protection) .

Now these days its better to use solid state as the longevity of these old relay based systems were never good.

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It's called an anti-plug(ging) or "AP" relay but you may not find something suitable for a small motor.

A micro-PLC is probably your best bet, just write a few lines of ladder logic to make it happen.

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Here's a slightly unusual arrangement that I've just invented using standard relays. It relies on the back-emf holding one of the relays on to prevent reversal until the speed has dropped to an acceptable value.

schematic

simulate this circuit – Schematic created using CircuitLab

Figure 1. Sudden motor reversal protection.

How it works:

  • If forward is selected the motor runs forward.
  • RLY2 will energise.
  • If FWD is released the motor will stop normally. While the motor speed is decreasing it will act as a generator. RLY2 will remain energised until the voltage drops - typically to about 1/2 or even 1/3 its rated coil voltage due to hysteresis.
  • If, instead, the switch is instantly thrown from FWD to REV then RLY2 being energised interrupts the supply from the REV contact until the motor has slowed down.
  • When the generated EMF drops sufficiently RLY2 will drop out and V+ will be connected to the lower terminal of the motor causing it to run in reverse.

On switching from REV to FWD RLY1 will provide similar protection.

Can anyone see a flaw with this (other than the OP never told us that it's a DC motor).

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  • \$\begingroup\$ there should be a run through non energized contacts of the non energized direction, so when it the opposing relay energizes, the other relay d-energize . This is what they call direction interlock and its a standard circuit in industrial motor control \$\endgroup\$ – drtechno Jan 21 '18 at 22:42
  • \$\begingroup\$ Bedtime in Ireland. Go ahead and hack my circuit into your own answer. I work in industry and am familiar with the technique but what are we protecting against in this case that the existing relays don't? \$\endgroup\$ – Transistor Jan 21 '18 at 22:46
  • \$\begingroup\$ overall, the guy probably needs a motor brake circuit for quick direction reversal. But depending on what type of motor it is, what method would be better. Those old Warner DC motor controllers were maintenance pigs mainly because of this type of control technology. I wouldn't attempt this except with AC motors, and even then, SSR i would use on them. \$\endgroup\$ – drtechno Jan 21 '18 at 23:01
  • \$\begingroup\$ not going to work particularly well on series motors, or induction motors. \$\endgroup\$ – Jasen Jan 22 '18 at 7:37
  • \$\begingroup\$ @Jasen: Correct. It would only work on a permanent magnet DC motor. OP hasn't responded to any questions or posts so we have no idea what motor it is. For some reason I imagined something smallish. Others have imagined something largish. \$\endgroup\$ – Transistor Jan 22 '18 at 13:34

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