4.5 DC power

[h90]

Hope here are some electric specialists......

I have a machine that needs 4.5 Volt buffer battery, unfortunately it needs more and more electric: Now it sucks 6 of the bigger (is it called D Cell?) dry in 2 month instead lasting 3 years on 3xAAA.

That is a known issue of this kind of machine. The battery is difficult to change.

Now I think to find a different solution.

4.5 Volt power regulator chip can be found, I think.

Than I thought feeding that small board over a car or motorbike battery which is always (or maybe just just 1 hour per day???) loaded.

That all can't be very difficult, even for someone who is a complete ignorant on electronics....

My questions:

Is that a good idea? Or shall I do something complete different?

Any recommendation on the 4.5 Volt power regulator chip?

How to safe load the big battery? I read that car batteries don't like to be loaded all the time, and does loading the battery mess with the 4.5 Volt regulator chip?

Any ideas?

thx

h90

PS.: It is an old CNC lathe with Sinumerik 810T controller....

[Crossy]

Do you know how much current it's actually drawing?

I'd be looking at a Q&D solution with a bike or sealed lead-acid battery and 12V => USB power unit, the lathe will be just fine on 5V but if you're worried stick a 1N4007 diode in series to drop it down to about 4.4V.

Cheap and easy.

EDIT a while back I got a few of these to make a USB charging station, would do your job perfectly http://www.satistronics.com/lm2596-dcdc-step-down-adjustable-power-supply-module_p2775.html.

[h90]

Do you know how much current it's actually drawing?

I'd be looking at a Q&D solution with a bike or sealed lead-acid battery and 12V => USB power unit, the lathe will be just fine on 5V but if you're worried stick a 1N4007 diode in series to drop it down to about 4.4V.

Cheap and easy.

EDIT a while back I got a few of these to make a USB charging station, would do your job perfectly http://www.satistronics.com/lm2596-dcdc-step-down-adjustable-power-supply-module_p2775.html.

Not much current....now it is connected on two sets parallel of 3 batteries D size serial

-1.5-1.5-1.5-

-1.5-1.5-1.5-

and they were empty in 2 month. BUT just one set was empty, so I guess on the other was a clip loose and before it last something like half a year.....

Anyway that doesn't mount up to much currency.

Taking your idea and modify it....let me know if it sounds right or if I talk nonsense:

Taking a computer UPS (it may has already a USB, or maybe not), plug in a quality phone USB charger in the 220 Volt side and get 5 Volt out of it.

for increased safety put in the diode and after the diode a big fat capacitor (in case the DC is not clean or there is a fraction of second without power when electric fails).

Don't know if there is some easy safety device to ensure no higher than 5 Volt can enter the machine???

Alternative it happens that I have this part on the link you gave. I saw it on ebay for 1 or 2 USD including shipping a few month ago. I couldn't believe that price and ordered it just for fun. It need 2 month to arrive but it did. So I have that part.

Is it smarter to use the UPS and take use this part to go from 12 Volt to 5.1 Volt and than with the diode? My thought is that if the mobile phone charger fails it is connected to 220 Volt, but this device is just connected to 12 Volt.

(if the CNC board is fried it costs me 1000-2000 Euro + a lot of headache as old as it is I must steal a replacement board from a museum)

(I am happy...from my complicate homebrew idea I am now at two different simple solutions If we ever meet I own you all the beer you can drink )

[Crossy]

How about something like this:-

Make R1 about 220 Ohms for a charge current of 25mA, the batteries will easily handle that forever and will also hold down the voltage to safe levels should something untoward occur with your electronics.

For simplicity replace T1, BR1 and C1 with an off-the-shelf wall-wart power supply (9 - 12V ish) and you're good to go.

[h90]

How about something like this:-

battery backup charger.jpg

Make R1 about 220 Ohms for a charge current of 25mA, the batteries will easily handle that forever and will also hold down the voltage to safe levels should something untoward occur with your electronics.

For simplicity replace T1, BR1 and C1 with an off-the-shelf wall-wart power supply (9 - 12V ish) and you're good to go.

I think I just go with this: http://www.invadeit.co.th/product/ups/cyberpower/bu600e-as-ups-600va-360w-p017728/

and plug in a mobile phone charger and maybe a capacitor to have it clean.

(I have an older Nokia and a newer Samsung charger) So I would only need to by the capacitor.

Sounds good?

[kovaltech]

My question ?

Why do you need these battery's ? do they hold data - programs ? then you'll definitive need battery

If not you can use a good -safe adjustable power supply. ( switched power supply )

Depending the quality from the battery's , they will last longer. Its very difficult to tell which brand or which type is better.

A trick is dough to compare them by weight... ( the heavy ones last longer, not a joke )

You also can use , in conjunction with a switched power supply, a small Li-ion battery pack, available in different voltages and for safety ad the protection-diode as Crossy described.