In these days of smartphones and the like, there's still space for 1920's technology

[Crossy]

Case in point.

 

Madam had a requirement for a "gates open" light. We can no longer see our electric gates from the house due to green things growing, so some sort of remote indication of the gate position became necessary.

 

Persusal of the gate controller manual revealed two useful outputs:-

• Gates Moving (a 1Hz flash).
• Courtesy Light (on when gates not closed).

Both signals are 220V and intended to drive lights.

 

Gates Moving is only active when the gates are moving (obvious really) but is off when the gates are closed or open.

Courtesy Light is active from the moment the gates start opening to when the finish closing.

 

Courtesy Light would do, but being me I decided that at 1Hz flash when the gates were moving and a constant on when open would be nice.

 

Enter a spot of relay logic to combine the two signals, a 220V relay and some wires. Drives an LED in an outdoor bulkhead fitting where Madam can see it and two small indicators on the gates which I can see from the car (because I could).

 

 

[Fruit Trader]

For complete satisfaction from both outputs . .

 

 

 

[Crossy]

9 minutes ago, Fruit Trader said:

For complete satisfaction from both outputs . .

 

I did actually look at this kind of indicator, negatives, they're not cheap, most are not weather-proof, needs 3-core cable to the indicator.

 

And of course I had the bits in-stock ????

 

 

[Jan Dietz]

To save wear on the relay I'd have flipped the two inputs, less clicking and clacking.

[Crossy]

Just now, Jan Dietz said:

To save wear on the relay I'd have flipped the two inputs, less clicking and clacking.

 

And get the same result?

 

Can you draw that?

[Jan Dietz]

Ah you're right of course. It's a NOT function, the flash is reversed on the 'main' warning line.

So ignore, live with the satisfying clacks ????

 

[Crossy]

13 minutes ago, Jan Dietz said:

live with the satisfying clacks

 

In reality you can only hear the relay when right next to the control box, and the light flashes about 20 times for each gate movement. At an average of six to eight movements per day I expect the relay will outlast me ???? 

 

I do quite enjoy doing these simple things, it keeps the grey matter active.

 

[Jan Dietz]

I see you removed the challenge, but this would be my solution, maybe we should have a thread for 'interesting stuff' : ) 

It did prove I'm rusty with Eagle... need to step it up ????

 

 

Relays are massive overkill but I didn't feel like drawing up a bunch of FETs

If you have a DPDT switch you can do without the relay. 

Power draw ~5mA to light a LED

Edited April 27, 2019 by Jan Dietz

[Crossy]

11 hours ago, Jan Dietz said:

I see you removed the challenge

 

Since there's been a response here is the "challenge".

Quote

 

Re-worded slightly from the original.

 

• Two points (house and gates) have an existing two-core cable between them.
• There's a doorbell in the house and a bell push on the gates.
• There is also a push button in the house to operate the gates.
• The gate controller needs a dry contact closure to operate.

 

How to link the two to make it work without pulling extra cables? (distance is too great for a wireless solution).

 

There's power available at both ends.

 

 

@Jan Dietz I quite like the idea of an "Interesting Stuff" thread, let me give that some thought.

 

[4evermaat]

why not just use motion-activated lights?   I went to this restaurant as dusk approached and then I noticed these small lights that were dim until I drove past each of them....they became brighter.

 

Not sure if they are 100% solar charged or were connected to the home electrical grid.

[Crossy]

How about this, single pole switches, power only at one end and no relays (one would be needed to operate the bell).

 

[Fruit Trader]

2 hours ago, Crossy said:

How about this, single pole switches, power only at one end and no relays (one would be needed to operate the bell).

 

Half wave switching. Can use cheap AC SS-relays which have built in opto isolation.

Edited April 28, 2019 by Fruit Trader

[Jan Dietz]

You may want to add a couple of decent capacitors parallel to D1 and D5, these opto couplers will switch 50 times a second without breaking a sweat. 

For the bell use a Triac opto coupler, they will drive up to 1A directly.

[gunderhill]

On 4/27/2019 at 5:59 PM, Crossy said:

 

I did actually look at this kind of indicator, negatives, they're not cheap, most are not weather-proof, needs 3-core cable to the indicator.

 

And of course I had the bits in-stock ????

 

 

I find here that most  plastics in the tropical sun simply disintegrate so I always  put some sort of cover usually stainless  steel  around them to protect from direct sunlight.