[istrumit]

Hello All

I blew out my DC-DC converter (14-28v) due to an alternator issue.

Its an Ameriking AK-550-12, so, great, as you all probably know, they are OTS.

I found one on eBay, but its an older model and the dimensions are wrong (too wide). The seller won't take it back, BTW...still working on that.

I would and could easily fix mine, but, the entire thing is potted in epoxy when I opened it up. There is no way to replace anything. Its all buried in black epoxy.

Anyhow, I need an AK-550-12 if anyone can suggest where I mind find one laying around in a demo bin somewhere.

Else, I am going to have to figure how to retrofit a Lone Star.

Thanks in advance !

Scott

 

[rv7charlie]

Don't know your situation (whether you fly hard IFR, fear Chinese products, etc) but there are lots of DC_DC inverters on ebay that can easily do the job, if you're willing to adapt connectors & mounting. All will likely be much smaller and more efficient than the old 'certified' inverter. I'd have used an ebay special on my 28V 430, but the seller threw the inverter in the box when I bought his 430.

Here's one example:
http://www.ebay.com/itm/Waterproof-DC-12V-to-24V-10A-240W-Step-up-DC-DC-Converter-Regulator-Boost-Module-/272574605057?hash=item3f76b66701:g:0yEAAOSwAPVZFmrF

It supplies 24V, which is what you'd get if your alternator was off line in a 28V a/c.

This one:
http://www.ebay.com/itm/DC-DC-600W-10-60V-to-12-80V-Boost-Converter-Step-up-Module-car-Power-Supply-SE-/232304462432?hash=item36166cca60:gMkAAOSwgQ9Vk4lR

should be good for around 6 amps (derated) at 28V.

No personal experience with either product, but there are lots of choices out there if you're willing to try them.

Charlie

 

[lr172]

Don't know your situation (whether you fly hard IFR, fear Chinese products, etc) but there are lots of DC_DC inverters on ebay that can easily do the job, if you're willing to adapt connectors & mounting. All will likely be much smaller and more efficient than the old 'certified' inverter. I'd have used an ebay special on my 28V 430, but the seller threw the inverter in the box when I bought his 430.

Here's one example:
http://www.ebay.com/itm/Waterproof-DC-12V-to-24V-10A-240W-Step-up-DC-DC-Converter-Regulator-Boost-Module-/272574605057?hash=item3f76b66701:g:0yEAAOSwAPVZFmrF

It supplies 24V, which is what you'd get if your alternator was off line in a 28V a/c.

This one:
http://www.ebay.com/itm/DC-DC-600W-10-60V-to-12-80V-Boost-Converter-Step-up-Module-car-Power-Supply-SE-/232304462432?hash=item36166cca60:gMkAAOSwgQ9Vk4lR

should be good for around 6 amps (derated) at 28V.

No personal experience with either product, but there are lots of choices out there if you're willing to try them.

Charlie

Let me know if you go this route. I fab'ed up my own 28 VDC supply as I didn't want to spend $400 for the lone star when I put in my 430W and KY96. Through some research and trial and error, I found some units that had ripple as low as lone star's unit and are low noise, due to high frequency switching. They are only rated at 4 amps, so I ganged up 4 in a box to handle the 12 amp load and provide some redundancy. They have not introduced any noise related issues in 100 hours of service.

 

[rv7charlie]

The AK-550 that I got with my used 430 is only rated at 6A output (obviously will draw a little over twice that off the 12V bus). IIRC, only the comm section must be powered by 24/28V, so I wired mine to run everything else off the a/c bus.

If my memory (and reading of the docs) is correct, you could have gotten by with two, or use one similar to the one I linked. Unfortunately, the 6/7A adjustable one doesn't come in a case, but the fixed output 24V model should work fine. I've been tempted to order one, just because the AK-550's mounting scheme is such a joke for anything intended to work in a moving body.

Charlie

 

[lr172]

The AK-550 that I got with my used 430 is only rated at 6A output (obviously will draw a little over twice that off the 12V bus). IIRC, only the comm section must be powered by 24/28V, so I wired mine to run everything else off the a/c bus.

If my memory (and reading of the docs) is correct, you could have gotten by with two, or use one similar to the one I linked. Unfortunately, the 6/7A adjustable one doesn't come in a case, but the fixed output 24V model should work fine. I've been tempted to order one, just because the AK-550's mounting scheme is such a joke for anything intended to work in a moving body.

Charlie

Sorry, I wasn't clear. They were rated at 4 amps at 12 volts. I needed 3 amps @28V for the 430 and 6 amps @28 V for the KY96, so 3 just covered the load (these are transmit loads, so not used simultaneously.). That said, the limiter is heat and because the only real load is during transmit, the duty cycle requirement is very low.