That relay circuit looks to be wired wrong!

Here is what a quick google found;

 

ok will keep that in mind RB , thanks

 

I looked around a bit and didn't see a single photo-interrupt switch that could drive your solenoid directly. Most support an output below 100mA (usually less than 50mA) and this could drive a small relay without other circuitry, so it could be used in place of the reed switch as long as you're using the relay configuration. I'm not sure about the ratings of the auto relay, though - you may need to find one with a lower coil current requirement.

Instead of using a relay at all, an optical switch and a MOSFET transistor would easily (and cheaply) drive your solenoid. I think this is how I'd do it personally. (The reverse diode across the solenoid is still needed.)

 

Something else to consider is the noise made by the relay. I once used a relay to flash some Christmas lights. The click-clack was very annoying and that project was rapidly abandoned. Would the noise be an added attraction or a distraction for your project?

 

Hi again Wayne and Alec, I am a bit overwelmed with so many ideas of doing this task. I did buy the auto relay today so tomorrow i want to build the circuit, could you kindly show me the circuit diagram you would construct from with a sort of shopping list of parts and links?

Although i do understand what most components do in circuits and the analogy of the plumbing system with inputs and outputs, something is missing. I teach art to people and i see my self in others when they cannot see what is obvious to me, this is my relationship with electronics, i did have a few electronics kits as a boy as well


Thanks

 

I was just passing by, thought this might help. Radio Shack should have diodes or something similar.

 

Hey wow, thanks Bernard, will try that one !!!

 

Thank you all , especially Bernard for his circuit and the suggestion of using the auto relay from Wayneh, the pendulum now works well without overloading the reed switch.

 

Cool, thanks for the feedback.

Just idle curiosity: Why do you need such a large boost to swing your pendulum? With good bearings, it should take very little energy on each stroke to keep it swinging.

 

The pendulum frame is one metre high and pendulum body pretty heavy, made from brass struts and an oak and steel head. it has good bearings as well. It does take very little energy to start it swinging. the voltage has gone up to 18 though.

 

The pendulum ran all day

 

When the reed switch disconnects the coil, it creates a high voltage spike which sooner or later distroys the read switch. You need a free wheeling diode accross the solenoid ( examples http://ichaus.biz/wp8_whitepaper_en ).

 

Thanks for the photo, looks interesting!

What is the weird pattern on the bottom plate, and what does the inlayed writing on the uprights say?

 

Hi RB

The weird pattern is veneer inlay to mimic the movement of the swing and the words are Anticipation - Ecstasy Birth - Death. It is part of a 3 piece work of Art made from oak

 

Hi IC man,

What do you mean by a free wheeling diode? Your attachment link was a bit beyond me... Sorry my knowledge of electronics is still newborn. Could you kindly show me the necesary modifications in the circuit diagram earlier in the this thread by Bernard, that i have used thus far and has worked for 5 hours without fail.

best

Derek

 

As shown in post 26 relay coil & solenoid both have 1N4001 snubbing diodes. Were they used??

 

Yep i used both of them and it worked... waiting to upload a vid of it working

 

https://vimeo.com/98594829

 

Very cool. I love pendulums. My favorite was the big one at the Smithsonian, which I got to see as a kid.

I still think you could use a MUCH smaller (and quieter) solenoid.

 

There is a Foucault's Pendulum in London's Science Museum, i must visit it again.

I like the sound of the pendulum i have made, it does sound like a heart beat sort of strong but fragile.

I am making 3 objects, each measuring or counting time, the pendulum is seconds another minutes and the third an hour, i will probably need advice again when i come to them...

The current pendulum now actually runs on 24 volts at 1.4 amps any less and it stops, the solenoid is rated between from 12 to 36 volts, i am using bench supply. How would i power it for exhibition or do you know way i can reduce the power consumption? I am, however sort of reluctant to change things as it is working, but we shall see.

all the best


Derek