Source for a Picaxe compatible Solenoid in OZ

craigcurtin

Senior Member
Guys,

I want to source a Solenoid that can be used to press a reset switch. (I have a boiler that occasionally locks up for no good reason and needs a "kick in the guts") occasionally.

Does anyone know of a source for these type of solenoids (as against valves) in OZ ?

Craig
 

Grant Fleming

Senior Member
I want to source a Solenoid that can be used to press a reset switch. (I have a boiler that occasionally locks up for no good reason and needs a "kick in the guts") occasionally.
Does anyone know of a source for these type of solenoids (as against valves) in OZ ?

Hi Craig,
I would be inclined to locate the "reason" whether it is good reason or not! A reset button is used after the fault is located and rectified. Continualy pressing in the reset button could be stressing the boiler until it fails (sometimes catastrophic).
A reset button is designed from the ground up to be slightly pressed by a finger, not a solenoid thumping against it.

Cheers,
Grant
 

D n T

Senior Member
can you use a higher current/voltage than your picaxe circuit??

If you can, then go hold of a HFS33 solid state relay and use their little solenoids

It also has a "sister" relay for AC, could you set up a by pass to do the job electrically of the reset switch?

If it has to be manual, how much force and traveldo you need ( how long is a piece of string?)
 

Grant Fleming

Senior Member
By DnT.. "could you set up a by pass to do the job electrically of the reset switch?"

This is getting worse! Now the talk is about bypassing the reset! The reset is sometimes the safety thermostat, boilers are not to be messed with.

Grant
 

Michael 2727

Senior Member
It may pay you to find the cause of the problem, then you won't need to press the reset.

The Plant next door has a large gas boiler which used to fail to ingite and causing an alarm to ring, this happened nearly every night (10.30pm - 2.00am) for 2 months. I got tired of ringing the owner and he got tired of me ringing and waking him up, I tent to stay up late anyway.
Turned out to be a dodgy LDR and wire. It only took 4 visits from the boiler tech to find it.
As said above a solenoid will slam your reset button/switch to pieces. You would be better off with a 12V/24V activated, circuit breaker type switch, DIN rail mounting etc.
 

Grant Fleming

Senior Member
Michael2727
You were on the right track first up stating that the boiler needs fault finding- (and original type parts replaced if needed).
Just because pressing the reset re-starts the boiler doesn't mean the reset switch is faulty or needs bypassing or a circuit breaker installed instead! I'm sure you must know that a circuit breaker is an 'over-current' protection device, we don't know if his 'reset' is an overcurrent reset or an overheating thermostat cut-out.
And yes, of course it is illegal to tamper with boilers unless qualified, you can see why it is illegal from reading some of the previous posts!

Grant
 

craigcurtin

Senior Member
Thanks Guys, I have already been down this track (3 times with the supplier) for finding the fault and they have no idea - the have replaced nearly everything in the boiler.

All the safety circuits are still in place. The boiler currently has thermostat override set to 40c where it will stop producing heat.

What happens now is that i monitor the temp of a tank of water - when it falls below a set point i energize a PICAXE level relay which in turns energizes a 240V relay and provides power to the boiler.

It then energizes its ignition circuit, which in turn lights the gas and then energizes its circulating pump.

For some reason the ignition circuit does not respond once a week or so. Currently i am tracking this (checking the temp of the tank 10 minutes after i call for heat and if it has not risen then sounding a PIEZO). However climbing as ladder at 2AM in the freezing cold to press the reset is getting old fast.

My plan is to use the solenoid once this situation has been detected to try and replace the manual intervention. If after this has been fired once we still do not have a heat rise in 10 minutes then i will have to ask for manual intervention.

So no i do not intend to willy nilly be thumping the reset switch and nor is there a good technical explanation as to why this is happening - the boiler supplier states that it could be a myriad of factors - in the end trying to blame the relay circuit from the picaxe, after i demonstrated to him how that worked he was fine in the end.

So back to the original question - does anyone know of a supplier in OZ - yes i am OK to go through a relay to drive higher current/voltage units

regards

Craig
 

Ralpht

New Member
Hi Craig,
I may have missed something here - is your reset button an "normal electrical switch" or is it some form of mechanical do-hickey.
The only time I ever had anything to do with resets on boilers, the reset switch was an normal electrical N/O (normally open) switch.
If it is an electrical switch, you can simply wire a relay contact in parallel with it (usual saftey processes to be followed of course) and there is no need for a solenoid.
If it is a mechanical reset switch than..
I enquired with a few people who should know and there is nothing available that they know of that is designed to do what you want. Your best bet is to get any available solenoid with characteristics close to what you need; ie voltage, throw distance etc, and jury rig it to fit your intended application.

 
 

craigcurtin

Senior Member
It is a mechanical switch. Little red button that protrudes about 1cm. When pushed there is an audible "click" and the boiler ignition "glow plug" kicks in and the Gas Valve is auto opened for the ingition.

I do not want to bypass this, just reset it when required.

Yes i do want to find the mechanical solenoid you have described - i just do not know where to look in OZ

Craig
 

inglewoodpete

Senior Member
Craig, A place the start is RS Components (in Aust) http://www.rswww.com.au/ I entered "solenoid", which returned 1008 hits (all sorts of devices), then filtered on "Cylindrical and Tubular Solenoids" (41 results). You can filter further on the power required (watts or newtons).

RS are not always the cheapest but I have found them to be reliable with prompt delivery.

You will need to determine how much force is required to press the buttons. This can be in kilograms and converted to newtons.

I think Jaycar and Dick Smith have a small range of hobby type solenoids which may have enough power to operate a light-action button.

-Peter
 

BCJKiwi

Senior Member
Are you sure this is not an electrical switch?.
If pressing the button powers a 'glow plug' to light the gas, the button you press must be closing a circuit somewhere.
Many push button switches - specially of higher voltage/current capacities have snap action internals so there is a positive closure so the contacts won't arc if you don't press them hard enough or let the pressure off a bit once closed.
These can make quite a bit of noise - specially at 2am!

BCJKiwi

 
 

boriz

Senior Member
Here in the UK, my (council house) boiler was causing problems. When lots of hot water was required for a bath, we switch the heater on and a little yellow LED lights up to indicate that the ignition system is attempting to light the boiler. There follows a few loud clicks as the sparking system works, then a satisfying ‘whumph’ as the main gas flames ignite. Then the LED turns to green, indicating that the water is heating up.

If the gas fails to ignite after a number of tries (clicks), then it stops trying and the light turns RED. Simply pressing the reset was usually enough to get it working. IF YOU NOTICED IT TURN RED!

Unfortunately this would happen frequently, and silently. We were often expecting to get into a hot bath but finding the water was lukewarm or cold. So we had to try it again, and wait another 30 minutes or more.

My plan was simple. Build an electronic monitor circuit that would beep loudly when the light turned red. I tried lots of optical methods. Phototransistor and filters. But nothing was satisfactory. Until, one day a council (sub contracted) service engineer took the fireplace off the wall for cleaning. I asked him if it would be ok to solder some wires onto the back of the LED PCB. He said he didn’t mind. So now I have a fully functioning warning system and no more lukewarm baths. Nice.

However. Another service engineer (council employee this time) was shocked to find these wires coming out of the side of the fireplace, and he shut off the gas until ANOTHER engineer could come out and remove the wires. He just clipped them with pliers. We got an ear bashing and were without gas for a week. Back to square one.

Bloody regulations.
 

Michael 2727

Senior Member
Craig you could try the Electrical wholesalers, e.g. L&H, Auslec, Middendorp etc.
Where Electricians get supplies,they should a good range of 12V/24V AD/DC relays.

Take the part # of you existing reset with you they may have a relay version of it.
And will probably be cheaper than Farnell or RS <img src="wink.gif" width=15 height=15 align=middle>
 

craigcurtin

Senior Member
Thanks Michael et al for the responses.

It is definitely a mechanical interlock of some description - this does not get reset with the simple power off etc.

I have ordered a push based Cylinder Solenoid from RS and will try that and let everyone know how i go

Craig
 

premelec

Senior Member
Without commenting on the propriety of what you are doing I'd like to mention that in the past I've found some very hefty AC solenoids in old washing machines - to actuate clutches and such....
 

craigcurtin

Senior Member
Thanks Premelec. i will try the version from RS and will keep in mind the Washing machine route next time a council cleanup is on

Craig
 

Wrenow

Senior Member
Not commenting on the safety, etc. of what you are doing, but another approach would be an inexpensive hobby servo. You can easily use these to press the button (we do that all the time in RC Model Warship Combat), and the throw is, of course, easily adjustable with the Servo or Pulsout command.

In fact, the 3 servo controller board (AXE024) has a filtered power etc. for an O8M, and there are even some inputs available, if you need them. For your application, it might be better to use pulsout to press the button and and another pulsout to reset to neutral (&quot;unpushed&quot;). That way, the servo is not &quot;energized&quot; and can be manually moved in between commanded movements.

Nice thing about hobby servos, they are designed to be easily mounted.

Just about anyone in the Australian Battle Group (AUSBG.org), which has local clubs all over OZ, can show you examples of servos pushing buttons or valves. However they do not appear to have gotten into the Picaxe interfacing much as yet (we are working on that over here in Texas). ;-)

Cheers,

Wreno
 
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