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Original Pentax D-AC50 adapter (for k10d, ..., k-5 DSLRs) is hard to find and expensive, especially for purchase outside US.

So I aimed to find a cheap replacement.
I noticed that Canon CA-570 AC power adapter ($7.98 with free shipping at ebay) has the same characteristics as D-AC50:
Input Voltage: 100V-240V AC (50-60Hz)
Output Voltage: 8.4V
Amperage: 2A

The only difference is a tricky plug used by pentax.
A little googling and I found compatible plug MQ172-3SA-CV(50) Digi-Key Part Number H10485-ND (center pin is +V and shield is GND) (only $2.99).

I assume that the way using canon adaptor is more simple than described in the DIY AC Adapter for The Pentax K10D and K20D article.
The only problem for me is that I live in Russia and digi-key does not ship to Russia.
If you are intending to assemble adapter according to this advice, please make a noble deed, purchase 2 plugs and send me one, not pro bono (I will send the plug price and S&H fee to your paypal account).

[Chaladinax]

Question to all electronics experts : I've just found in another forum a promising info to build a cheap AC adapter for the K5 and others 8.3v's
I do not know if Pentaxforum.com allows me to share the link, but it's easy to find it using keywords with google...

The poster said the easy way is to use a Voltcraft USPS1000 power supply - or any other brand, able to output standard 9v.
then use the proprietary K5 connector plug MQ172-3SA-CV(50) with a diode connected in serial to the 9v output regulated.
according to the poster, the 0.7v diode voltage drop will then give you the 8.3v target for our baby.

What do you think ?

My questions are :
- 1 - Will it work ?
- 2 - would this power supply draw enough current for the normal operating of the k5 (I read somewhere that K5 could draw as much as 1.8A when writing a photo to the SDCard)
- 3 - would'nt our baby risk some kind of seizure with this setup ?
- 4 - Are you sure ???

sorry if my Q is kinda noob. looks like a too simple hack to me. But if it works, it will be great. You'll end up with a single power supply "nurse", able to fit many devices, including our lovely "baby" !

a promising idea for backpacking - and for the money diet !

[beholder3]

The Pentax original is available in Poland (for a whopping price of 119 EUR, twice the one from adorama) and seems to be in stock.
Zasilacz sieciowy Pentax D-AC50
For those desperately in need...

[Chaladinax]

Thanks for the info...but personaly speaking...I 'm not THAT desperate, not to spend so much for just ... a transfo ! I've been caught once, but I prefer to wait a little, and have the pleasure to do it myself. DIY is a state of mind....cost lot of energy to figure it out sometimes, but I think when you see it works as the original overpriced commercial product, it is very rewarding.
just good for the challenge, and for the Ego.

[jwoodland]

Just FYI, the Pentax AC50 adapter is finally back in stock at their online store...

[pwsheehan]

About $70 plus shipping and tax at Adorama.

I've already ordered the parts to use the Canon brick trick.

Will post when it's complete and tested on my K10D.

[birdandfly]

$49.95 at B&H, free shipping. Pentax K-AC50 AC Adapter Kit 39364 B&H Photo Video

[Predictor]

Cheaper and cheaper. I suppose when I receive the plug and canon adapter original one will cost no more than canon+plug combo.

[tybeck]

I will offer a cautionary tale for those making their own power connections. I made several attempts to do this with a 8.4 V/2A power supply I found at a local Fry's. It worked for my first cable attempt, but I ended up shorting out the power input on my K10D with my second attempt. With the Pentax AC50 power supply the camera longer powers up, just the blinking battery icon mentioned in a post above. Fortunately, it still powers up with a battery, so it is not bricked. Lesson learned, be careful making your cables.

I will also add that the pins on the power connector are very small. Helping hands and tinning your wires helps. I put on some shrink tubing on each pin to keep things in place after the final soldering.

[chromo]

I will offer a cautionary tale for those making their own power connections. I made several attempts to do this with a 8.4 V/2A power supply I found at a local Fry's. It worked for my first cable attempt, but I ended up shorting out the power input on my K10D with my second attempt. With the Pentax AC50 power supply the camera longer powers up, just the blinking battery icon mentioned in a post above. Fortunately, it still powers up with a battery, so it is not bricked. Lesson learned, be careful making your cables.

I will also add that the pins on the power connector are very small. Helping hands and tinning your wires helps. I put on some shrink tubing on each pin to keep things in place after the final soldering.

If you shorted the + and - in the plug, it will only affect the power supply, not the camera... The camera will not see any current if it's shorted.

You most likely used the wrong pins, wrong polarity or connections touching inside the plug.

Wrong polarity or voltage too high is the way to wreck the camera.

Try checking the output of the Pentax AC50 power supply with a meter to see if it's still working ok.


The 3rd link in post #9 shows 2 of the pins as connections and the shield is not used at all.

I thought I saw in another post about building this power supply and I think it was a 1N4001 diode that was mentioned.
The use of the diode is correct but it must be a 1N5404 as it will handle 3 amps... The 1N4001 only handles 1 amp.

Also : Element 14 (formerly RS Components) has the plug. About $3.50AU. No minimum cost if ordered online and free shipping.

[pwsheehan]

OK, using the special connectors and doing a little electronic investigation, the Pentax adapter must be "communicating" with the camera. I haven't figured it out yet, but I don't want to ruin my camera, so the "cheap" adapter idea is being put to rest for now. B&H has the Pentax adapter as a special order item for about $50 so I'm going to go with that and call it good. $50 doesn't so cheap considering it's better than possibly damaging or destroying my camera. Sorry. If I do decide to investigate more, I'll post any findings. (FYI, the three inner gold pins all showed different resistances with the camera off and then with the camera on, running on the battery, the voltage values were mixed as measured with a DMM. So I assume it's not a simple two-connection interface. My next investigation will look at these pins using an oscilloscope to see if there are any dynamic signals. I also noted that the AC50's cord from brick to camera is round like a multiconductor - more than two - cable. More later...)

[Predictor]

Test with CA-570 failed. Camera repeatedly turns on and off. Sometimes it's even possible to view last recorded image. But nothing more.

[Scootatheschool1990]

Has anyone done this and had a good result?

[LeFanch]

Has anyone done this and had a good result?

Hi,
I went the lasy way, using a regulator from DimensionEngineering...
All you need is a connector on battery side, the connector on camera side (MQ172-3SA-CV(50)), some wire to link those to the regulator.

Total cost for me, as I had a small battery (12V) and the wire : 29$.

I used it for several hours when taking pictures / videos of birds in a park nearby. That works very well.

I had also made an adapter based on Roamingdrones design, that worked fine, but I did not use it in "real life" conditions.

I hope that helps...

François

[Scootatheschool1990]

Any chance you could post pictures? I'm a novice at soldering and electonics. Thank you for your help already btw.

[LeFanch]

Unfortunately I will not be home before 28th July so I cannot post pictures right now. I will as soon as possible!