The motor in the disco ball had no load so it was not working hard. The motor turning your statue might be working hard.

The lamp that was connected in series with the motor reduced the voltage to the motor.

Therefore the motor was not hot.

The timing capacitor in the fading circuit charges positive then charges negative so it must be non-polarized.

__________________
Uncle $crooge

 

ok, when i buy more components i will get a non-polarized 22uF cap to replace the polarized one.

The motor has no load at the moment as it isnt attached to the sculpture yet

What can i do to reduce the voltage to the motor and replace that Lamp?

heres the specs of the adapter im using if you still need them ...
Model: MKA-120500UK
Input: 240V AC 50Hz
Output: 12V AC 500mA

 

For the cap, try to find something like this one.
http://search.digikey.com/scripts/Dk...me=445-2904-ND

 

The motor is a 12VAC which uses 1 Watt at 50Hz, according to your earlier post. The lamp uses 5 Watts. The adaptor is rated at up to 6 Watts (12 volts * 0.5 amperes). So in the disco ball, 5/6 of the current is drawn by the lamp, and the combined load of the motor and the lamp bring the adaptor's output to 12V.

Remember that the adaptor (unless it's regulated) is putting out quite a bit more than 12V with no load (or with a very light load, such as just the motor by itself). So with just the motor on it, the voltage the motor is getting is well over 12V. I suspect that's what's causing the motor to run so hot--it's getting an overvoltage and doesn't like it.

With the limits of my experience here, I'd think that your choices are:

1) Increase the load on the adaptor to bring the current consumption up to around 500mA and thus the voltage down to ~12VAC, which is what the 5W lamp is doing--but this wastes 5 Watts, which is quite a bit; or
2) Somehow decrease the voltage output of the adaptor without wasting the extra 5 Watts. Normally I'd use a transformer for something like that, but in this case I think it would be easier just to try a 12VAC output adaptor with a lower current rating (say, 100mA or so) or even try a 9VAC output adaptor instead.

There are other ways to do it but I'm trying to stay away from them since I haven't got much experience with them and I think they would be a whole 'nother project altogether.


Torben

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Curiosity was framed. Ignorance killed the cat.

 

i figured this was alot of trouble just to get the motor to work properly so i went and bought this...
12v DC Motor

Now i can keep the whole circuit DC. No doubt it will come with a whole host of new problems

 

From the eBay page I think it should work. We'll see when it arrives, I suppose.


Torben

__________________
Curiosity was framed. Ignorance killed the cat.

 

If you buy an unregulated 12VDC adapter then its voltage might be as high as 18V when the current is low. The fading circuit and DC motor not designed for 18V.
Same problem as before.

__________________
Uncle $crooge

 

It's 60 RPM at 12V. You definitely want to drive it with a lower voltage. I would recommend trying 3V first.

 

Yep, your right. Even just using a 9v battery to it, it is noisey and created too much vibration to be used how i wanted it to be Im sure i can find another use for it though....

What dc motors should i be looking at then?
It just needs to move about 20-40 rpm, 12v DC, be silent and no vibration, and be strong enough to able to resist you pinching the shaft.

 

If it's 60 RPM at 12V, it's pretty close to 20 RPM at 4V.

It's not necessary (and seldom desirable) to operate a motor at its maximum voltage/RPM.

 

I see.

I have put a 220 resistor infront of the motor to slow it down which has made a improvement to the vibrating it made
In addition to that, im planning on making a mount for it to sit on with a small wood frame and rubber bands to absorb the rest of the unwanted vibrations, whilst not letting it move around too much and mess the sculpture up.

and to top it off, ill put a box of polystyrene around it to hopefully muffle the noise the motor makes directly.

its going to take a bit of fiddling and time to make, but i think ill get there

 

Controlling motor speed with a resistor is not a very good way to go as you waste a lot of power. Some sort of PWM circuit would be better. Perhaps someone here has a easy circuit you could use. I will look around later.

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Forget injuries, never forget kindnesses.

 

*Sigh* Ive soldered the circuit all up to find that it isnt working....
The LEDs are not fading again and i am 100% sure the PCB is correct.
Im thinking maybe i damaged the chip while soldering it into place and it has accoured to me that i should of heat sinked it or used a 8pin socket.....

Is there anyway to test the chip to find if that is the problem?

 

Is this with motor connected? Can you try disconnecting motor?

__________________
Forget injuries, never forget kindnesses.

 

Can you define "not working"? Does that mean the LEDs are on all the time, off all the time, the motor is jerking but not rotating. . .or does it just behave exactly the same with power hooked up as it does with no power (i.e. it just sits there like a lump when you turn it on)?

Like Mike said, disconnect the motor and try again.

Check the voltage coming out of the power supply.

Check the voltage at pin 8 of the op-amp.

Double-check to make sure that the LEDs are in the right way 'round.

Look very very closely to make sure you don't have any solder bridges. It's quite easy to accidentally join two pins with a tiny bit of solder which can bugger up the whole thing.

That said, unless there is a dead short somewhere or the power supply is dead, I'd expect that at least the motor would turn, even if the fading LEDs portion of the circuit didn't work.

What are you powering it from now?

I'd say that using a socket is a really good idea unless you expect the circuit to be in a high-vibration environment. It eliminates the chance of solder heat killing an IC and allows you to easily swap in another IC to test.

Hopefully you still have your test prototype circuit set up so you can triple-check the connections.

Do you have a camera which can take good closeups? Cell-phone cameras usually have crap picture quality but a decent digital camera will often have a macro or manual-focus mode which allows you to get quite close. If you can post really clear, close pictures of both sides of the circuit board, perhaps someone will be able to see something you missed.

OK, back to my housework.


Torben

__________________
Curiosity was framed. Ignorance killed the cat.