This might be a stupid question about power!

[Northerner]

I want a replacement power supply for my fab Sharp GF9000E as mine was in a car accident (don't ask) so has no power supply in it. Now please bear in mind my lack of knowledge but I've just found out how watts amps and volts relate and reckon that if the Sharp uses 15v DC and the wattage is 45w according to the back plate, then do I need a 3A supply?

Is there any reason why I can't use something like one of these?

http://www.ebay.co.uk/itm/15V-3A-45...?pt=UK_Sound_Vision_Other&hash=item20c477a15b

Theres a ton of space in the Sharp and its a simple case of the red and black power cables running to the on/off switch and from there to the workings. Obviously I'd have to strip off the power plug on the power supply to reveal the + and - wires.

I'd also put in a main/battery switch so I can run from either.

What do you reckon or am I missing something and asking a stupid question?!

 

[Eddy]

The 45 Watt on the back plate is the power consumption @ 230 volt.
The toshiba power supply you linked is strong enough to power your GF 9000

 

[Superduper]

It should work although I have seen these types of power supplies wimp out when connected to boomboxes. Also the other thing you should know is that these are switching supplies unlike the old Analog/transformer supplies we are used to (and which was OEM on that and other boomboxes). The technology is different and results depend upon quality. When of poor quality, they can emit enough electrical noise to render AM useless, and can even be heard over the audio. Basically, you would just have to try it and see.

The other thing you should do is measure actual voltage. These types of supplies are often designed to be used in applications that have built in voltage regulators so the output voltage might be much higher than the #'s specified on the label. In other words, it might be saying 15V AT 3A current draw. When current draw is less than 3A, the output voltage might be a whole lot higher than that. Test and be safe.

3RD: Personally, I would just rebuild the current supply. It's not that hard and would retain all the features such as AC socket, AC/DC/Battery switches, same technology, etc. I'm sure somebody on that side of the world could do it for you if you can't?

 

[Northerner]

Thanks for the advice, really appreciated, I'm gradually picking up info that's making me less and less dumb Might see if I can work on option 3...I have a brother in law I'm working on to get him to do some techie stuff for me but he doesn't know vintage stuff so this advice is very useful. Looking to get my self a book on electronics too to get me more up to speed.

Thanks guys

 

[kraftmatic]

I appreciate these posts too, lots of into to learn from. Good luck, let us know how it turns out.

 

[Cpl-Chronic]

Is there any reason why I can't use something like one of these?

http://www.ebay.co.uk/itm/15V-3A-45...?pt=UK_Sound_Vision_Other&hash=item20c477a15b

Theres a ton of space in the Sharp and its a simple case of the red and black power cables running to the on/off switch and from there to the workings. Obviously I'd have to strip off the power plug on the power supply to reveal the + and - wires.

I'd also put in a main/battery switch so I can run from either.

What do you reckon or am I missing something and asking a stupid question?!

[ Image ]

You don't need to re-invent the wheel, so to speak, if your box has a 15v DC jack built in & working. If your blaster takes 10 D cells or uses a 15v DC jack, you can simply plug a 15v laptop AC adapter into the DC jack of the blaster & the blaster's internal circuits will do the switching for you. Even 90w laptop power bricks are cheap now & you don't have to rig anything special to use it.

 

[oldskool69]

Is there any reason why I can't use something like one of these?

http://www.ebay.co.uk/itm/15V-3A-45...?pt=UK_Sound_Vision_Other&hash=item20c477a15b

Theres a ton of space in the Sharp and its a simple case of the red and black power cables running to the on/off switch and from there to the workings. Obviously I'd have to strip off the power plug on the power supply to reveal the + and - wires.

I'd also put in a main/battery switch so I can run from either.

What do you reckon or am I missing something and asking a stupid question?!

[ Image ]

You don't need to re-invent the wheel, so to speak, if your box has a 15v DC jack built in & working. If your blaster takes 10 D cells or uses a 15v DC jack, you can simply plug a 15v laptop AC adapter into the DC jack of the blaster & the blaster's internal circuits will do the switching for you. Even 90w laptop power bricks are cheap now & you don't have to rig anything special to use it.

I'm guessing that, and likely why Option #3 was presented, he would like to keep the box original. This way when and if he does sell it, that exactly what it is reconditioned. But it sounds to me like someone has some thinking to do to get the box where he wants it.

 

[Northerner]

It's missing its transformer and the circuit board and sockets attached...that whole section was taken out and binned by the dopey previous owner...so there is no 15v socket to plug into. At the moment it has nothing there, just a big empty space I diverted the power wires direct to the battery terminals and I run it off 10 D's. I've spent many hours restoring this to look original but have no objection to using a non-original transformer (mainly because when I asked if anyone had an original one for sale no one did). Nearest I got was a GF575 which, although has the same rating, is wired up completely differently and I couldn't work it out. As I say I think I'll go for option 3 or see if my brother in law can help with the 575 one.

 

[Cpl-Chronic]

OK...option 4....is the 15v DC socket still there? IF so, it should have a switch built in & you can wire it up to switch the batteries on/off & supply the boomer like that with a laptop supply as I mentioned before, say a 90w bar so you have plenty of power. Juat an idea.

 

[Northerner]

OK...option 4....is the 15v DC socket still there? IF so, it should have a switch built in & you can wire it up to switch the batteries on/off & supply the boomer like that with a laptop supply as I mentioned before, say a 90w bar so you have plenty of power. Juat an idea.

No there is nothing there other than an empty space, no sockets, no circuit boards, no switches, nothing but fresh air...that's why I've wired battery terminals to the on/off switch.

 

[Beosystem10]

Hi Northerner, I'd be happy to help with this if you happened to be passing this part of the country at some point. I could help you to get your GF575 PSU to suit your box and could add a DC input from a scrapped laptop or similarly distressed modern gadget. Think of this as another option to fall back on. Same goes for any other local members who may need support with their restoration work.
I have 30+ years of experience and restore ancient electronic kit week in and week out.

 

[Northerner]

Hi Northerner, I'd be happy to help with this if you happened to be passing this part of the country at some point. I could help you to get your GF575 PSU to suit your box and could add a DC input from a scrapped laptop or similarly distressed modern gadget. Think of this as another option to fall back on. Same goes for any other local members who may need support with their restoration work.
I have 30+ years of experience and restore ancient electronic kit week in and week out.

That's awesome John! Might just take you up on that kind offer...as I say the 575 all works and is the same rating, just don't follow what all the other connections do etc Spent so long doing up the 9000 I don't want to kill it at the last stage. You're probably only an hour or so away from me so its definitely workable. Cheers mate, I'll keep this option in reserve. Good to know I can definitely sort it one way or another now

 

[Northerner]

It should work although I have seen these types of power supplies wimp out when connected to boomboxes. Also the other thing you should know is that these are switching supplies unlike the old Analog/transformer supplies we are used to (and which was OEM on that and other boomboxes). The technology is different and results depend upon quality. When of poor quality, they can emit enough electrical noise to render AM useless, and can even be heard over the audio. Basically, you would just have to try it and see.

The other thing you should do is measure actual voltage. These types of supplies are often designed to be used in applications that have built in voltage regulators so the output voltage might be much higher than the #'s specified on the label. In other words, it might be saying 15V AT 3A current draw. When current draw is less than 3A, the output voltage might be a whole lot higher than that. Test and be safe.

3RD: Personally, I would just rebuild the current supply. It's not that hard and would retain all the features such as AC socket, AC/DC/Battery switches, same technology, etc. I'm sure somebody on that side of the world could do it for you if you can't?

Well it looks like I'm going for option 3!

Been in discussion with an electronic engineer from Marshall Amps who I'm lucky enough to be related to and he's building me a new power supply. Given him all the specs and measurements and he's gonna sort it for me...will be so chuffed to get this one running off mains instead of just 10 D's