Variable time on/off switch circuit, for model tree-house project

[Paul Louws]

I have a built model tree-house ( about 1m high ) and it even has 16 small lights 4.5V ( 3xAA's ) placed inside the cabins and going up the staircase etc etc. Well, I am displaying it in an arts and crafts show in about 6 weeks, and I would like to fit a small circuit that will turn the lights on for say 1 minute, then off for say 5 minutes in an ongoing cycle.

The main issue is it needs to be low power... I bought a small board with a timing IC that I thought would work, it did, BUT I discovered that the battery to drive it ( small 12V ) dies very quickly ( few hours ), so I need something more simple to do this job, and would love some ideas / pointers. I am not a skilled, or even novice electronics hobbiest, the best I could claim is interested with the occasional dabble, but this time I do have a real project!

I look forward to any interest / ideas, Many thanks, Paul.

 

[Bluejets]

What is the loading?
i.e.LED's or torch bulbs?
What is the timing module?
You say you have 4,5v but then quote a 12v module.

 

[BobK]

Is the timer module using a relay? If so, that is using all the power.

How about posting a link to it.

Bob

 

[AnalogKid]

If you want to build a timer circuit from scratch, this can be done with a CD4060 oscillator/divider, a couple of small diodes, and an output transistor.

What is the peak current of the load being controlled?

Is 4.5 Vdc the only power source available?

ak

 

[Paul Louws]

Is the timer module using a relay? If so, that is using all the power.

How about posting a link to it.

Bob

Hi Bob, yes it is using a relay, thanks for your good guess... so I do need another solution to achieve the 1min or so ON / 5min or so OFF. Do you know if there is a simple solution to this?

The Lights are fed by 3 AA's giving 4.5V at about 150mA, so I need the occasionally on for the show, so that the lights will operate on/off for 5-6 days.

Many thanks,
Paul.

 

[Paul Louws]

If you want to build a timer circuit from scratch, this can be done with a CD4060 oscillator/divider, a couple of small diodes, and an output transistor.

What is the peak current of the load being controlled?

Is 4.5 Vdc the only power source available?

ak

Hi AK, The current draw from the lights is about 150-200 mA that is all, they are LEDs and the 3 AAs will last about 20 hours if constantly on, so my desire to have an on/off switch in the circuit is twofold... 1) to have the lights come on to impress the viewer, and 2) to have the 4.5V source last about 5-6 days.

Is what you have suggested basic and easy, maybe I could do it I have some 'parts' and an electronics JACAR outlet nearby, but it has to be LOW POWER CONSUMPTION... I need it to last at least 6 days also, hopefully more? I can have another battery pack to drive the on/off circuit.

Also I thought of doubling the 3xAA cells (in parallel) to get more Amp-hours?

Thanks heaps for your response.
Paul

 

[Paul Louws]

What is the loading?
i.e.LED's or torch bulbs?
What is the timing module?
You say you have 4,5v but then quote a 12v module.

Hi Bluejets...

They are 16 x LEDs and 4.5V drives that circuit, it would last about 20 hours
The small 12V battery was used to drive the relay switch... and died very quickly.

My desire to have an on/off switch in the circuit is twofold... 1) to have the lights come on to impress the viewer, and 2) to have the 4.5V source last about 5-6 days.

Thanks for your input,
Paul

 

[Paul Louws]

Hi everyone... Here was my relay module $3.50 no big deal, close, but one issue (relay power usage, as I now understand) that I need to solve... perhaps a very simple alternative circuit I hope, to using this more generic multi-use module. thx Paul

 

[Paul Louws]

I should let you see my model tree house so you know what the project is for.... ... keen to hear from you, Paul

 

[Engine9005ering]

Have you tried using photomos relay?

 

[Bluejets]

555 output will handle 200ma direct on pin 3.
I'm pretty sure those timers will operate down to 4.5v so get yourself a 5v version of what you already have or rather the 555 version and hack it.

BTW....impressive model work,......... like it.
I'm more into aircraft , choppers and boats myself.
Build my own 4 stroke engines and machining tools /machines.

 

[BobK]

D cells would get you to about 3 days constantly on.

A more sophisticated timer, one that allowed you to turn the lights on only during the open hours of the exhibition, would do it.

Ideally, the timer would run off the 4.5V battery and use an electronic switch rather than a relay. Not sure if that is available commercially.

Bob

 

[Paul Louws]

555 output will handle 200ma direct on pin 3.
I'm pretty sure those timers will operate down to 4.5v so get yourself a 5v version of what you already have or rather the 555 version and hack it.

BTW....impressive model work,......... like it.
I'm more into aircraft , choppers and boats myself.
Build my own 4 stroke engines and machining tools /machines.

Thanks Bluejets...
'Hack it' seems impossible to me, are you saying remove the large blue relay box and connect a 555 somehow?
I am thinking it would be easier to use a breadboard with a 555 and build it?

 

[Bluejets]

are you saying remove the large blue relay box and connect a 555 somehow?

No, not at all.
What I said was if you get a 555 version and hack that,

or/ you could hack your present unit by looking at how the relay is operated.

I think you will find the transistor adjacent to the relay is the one that operates it.
Either get some numbers off it to determine what current rating it has or/ replace it with a larger current handling transistor.

You already have the basis of a widely variable application timer with the chip attached so surely a small mod will see you being able to switch 150mA.

 

[Paul Louws]

Hi GUYS, PROBLEM SOLVED, thanks heaps for your input I love learning new stuff (I am a retired Civil Eng), I bought a cheap digital multi-meter and started snooping around to understand better how the module I bought works, and as you thought it does operates on less voltage too. So I ordered a 5V version should work even better and have a lower power draw. I also wired up a few simple circuits with the help of the internet, and had some ideas about how to run it only during exhibition hours.... awesome, all that remains is installing the extra battery pack and timing module, plus some finishing touches to the model and it will be ready to Rock 'n Roll.

Thanks again, kind regards to each of you,
Paul

 

[Bluejets]

Well done.

 

[duke37]

If the leds are run at their maximum permitted current, it may be adequent to pulse them on for 50% of the time thus doubling the lifr of the battery.