12vdc to 5vdc? or a a 12vdc usb hub?

[MG1]

Hi Guys, after a bit of expert advice here...

I have a small belkin hub for which I don't have a power lead (never came with one) but believe it it's a 5vdc required. This is out on the mount and i'd like to tap some power to it, maybe off the kendrick.

So, what's the best way for me to convert 12vdc to 5vdc? I've seen some of these, but is that overkill?

RS | Power Supplies | Power Supplies, Inverters, DC/DC Converters & Generators | DC DC Converters | RS - 15 to 1000W Enclosed |SD-15A-5

Could I just use this:

Murata Power Solutions | Power Supplies | Power Supplies, Inverters, DC/DC Converters & Generators | DC DC Converters | Murata Power Solutions - 3A to 16A Non-Isolated, Point-of-Load DC/DC Converters |OKR-T/3-W12-C

As this will be potentially sending power to all my USB devices I really want to get this right...don't want to fry everything!

Any thoughts? I just cant seem to find an off the shelf converter which seems strange?!?!

Cheers

Michael

[Photosbykev]

I use this adaptor 3A Digital Car Power Adaptor : InCar Power Adaptors : Maplin powered from a 12v 110AHr battery to run a 7 port hub

[MG1]

cool, thanks Kev...Which hub are you using? I only ask because I'm begining to think my 4ports are not enough...am thinking of getting a temphum thingie to use with the APT so I remember to refocus mainly...oh and I'm complete nerd for anything that gives me data...

[Photosbykev]

cool, thanks Kev...Which hub are you using? I only ask because I'm begining to think my 4ports are not enough...am thinking of getting a temphum thingie to use with the APT so I remember to refocus mainly...oh and I'm complete nerd for anything that gives me data...

I use this hub 7Port USB 2.0 Hub in White : USB Hubs : Maplin

[citaylor]

You could use a Car cig lighter->usb adaptor, for example this one for 99p delivered!

You can take the 5v feed from the two outer pins...

[Photosbykev]

You could use a Car cig lighter->usb adaptor, for example this one for 99p delivered!

You can take the 5v feed from the two outer pins...

This isn't suitable to power a hub because it probably won't be able to deliver the current required to drive a hub as it designed to power a single usb slot.

Each usb slot should be able to deliver 500mA so a 4 port hub is normally fed by a 2-2.5A power supply

[davew]

Hi Mike,

I got a 12v regulator from John Rose a few years ago that supplies multi voltages. See - Astrodevelopments.com then click accessories. Works well and gives me 5v upto 2A. Even seems to work at minus plenty soaking wet but I don't recomend it and neither does John. I now use a small plastic box with most of the electronics in.

I also fell into the four port trap. I now seem to need five. I have looped another hub into the first giving seven available ports. A seven port hub would be more sensible but that wouldn't be me. Try not to get one like mine that has a bright blue light in it that illuminates the whole bottom field at Kielder. It was mentioned.

Dave.

[MikeP]

Michael,

Like Kev, I use one of these .... Universal 3A DC Power Supply : InCar Power Adaptors : Maplin .... to power a 7 port USB hub. I know it is only 3A but it is enough for my needs.

Typically I connect an EQ6 and Atik1 6HR (both of which have their own power supply), a SX filter wheel, SX Lodestar and a GPUSB (these three drawing power from the USB). I run all these from a 75AHour battery and have another 75AHour to run my laptop (if needed) and dew straps.

My hub is a Sitecomm CN035 (it uses a 5V supply) - I tried other cheaper hubs and found them wanting.

Mike

Mike

[MG1]

Thanks guys.

As Dave will know, I'm on a bit of a quest to have a tidy setup and am working on a 'hub' that will take 12vdc in and then power all my kit, 5vdc to a hub and possibly even whatever I need for my camera....annoyingly 7.2vdc I think!

I could just get the unit you've suggested and dismantle to include inside, but would quite like to know f it's possible for an amateur fiddler like me to make something.

Just curious I guess.

Thanks again!

[Photosbykev]

Thanks guys.

As Dave will know, I'm on a bit of a quest to have a tidy setup and am working on a 'hub' that will take 12vdc in and then power all my kit, 5vdc to a hub and possibly even whatever I need for my camera....annoyingly 7.2vdc I think!

I could just get the unit you've suggested and dismantle to include inside, but would quite like to know f it's possible for an amateur fiddler like me to make something.

Just curious I guess.

Thanks again!

The first RS DC regulator would be ok, plenty of capacity to handle a hub and a good range of input voltages. You would need all the supporting electronics to provide voltage adjustment and maybe a resistor across the output to ensure the voltage is stable. The second unit seems to need a minimum of 12v rather than a wider voltage range, as your main battery runs down the voltage might drop below 12v which could causes problems with the 2nd option.

7.2v sounds a bit low for Canon bodies, typically they are 7.4-7.5v and are very sensitive to lower voltages.

[MG1]

Cheers Kev

The battery on my 5dII says 7.2vdc 1800mA.

I think I need to do a little reading around circuit design before jumping into this one....will have to look out for an adult ed course I think!

Although that could be dangerous since that's how I started in astronomy!

[Photosbykev]

Cheers Kev

The battery on my 5dII says 6.2vdc 1800mA.

I think I need to do a little reading around circuit design before jumping into this one....will have to look out for an adult ed course I think!

Although that could be dangerous since that's how I started in astronomy!

I'm using the 5D MkII as well and I'm sure the working voltage is higher than 6.2v BUT I don't have it to hand to confirm it. I do recall that the camera can pull a couple of amps in certain conditions so the regulated supply needs to be at least 2A and should be in a box external to the camera body to reduce heat.

[MG1]

Ooops typo!

It says 7.2 on the canon battery...but maybe the power packs are rated higher?

Have corrected my other post.

[Psychobilly]

7.2V is the endpoint... charge it and measure it staight of charge and you might be suprised how much higher it is (the 1000D/500D come off around 8.2V)

I found that the camera like more voltage in cold weather for the 1000D/550D so I set my adaptors at 7.6V which shows one bar down on the battery meter in the summer and 1 bar remaining in winter when the temps in single figures...

At 7.2V I would get frequent hangups at 7.4V occasional ones at 7.6V they have been fine down to -10C

Billy...

[MG1]

Thats good to know...cheers Billy