Peter "Sci" Turpin

I’m aiming to finally build a wearable, and managed to find a cheap alternative to cutting a set of video glasses in two for a monocular. I got a broken analogue video camera off ebay that had a colour LCD viewfinder. It was a bit of a gamble that being analogue it would have simpler inputs than a digital camcorder, but it paid off. I received the camera today, pulled it apart and got it running on it’s own. 0.2A @5v with composite PAL input.

There’s a 4th pin on the connector though, in addition to Gnd, 5v and video. It’s marked “HD” on the viewfinder PCB, and I traced it back to the IC where (after going through a SMD transistor) connects to the “HD” pin 30 on the controller IC.

The datasheet for the IC expands it a little that the HD pin is for “HD pulse output”, but I can’t find anywhere that explicitly states what the HD pulse is.

I’m *guessing* it’s something to do with the frame timing since the only other HD I can find in the sheet relates to “Horizontal Direction”.

The IC is a Sony CXA1854AR by the by.

The camera supplies the HD pin on the connector with 4.3v however, or at least seems to. I thought I tested it for voltage with the display disconnected, but I’m not sure now. Rather sleep-deprived.

In any case I’m thinking it’s either a case of the IC pin using the transistor to pull the connector pin low, or more likely now that it’s actually a 5v output and my multimeter detected it at only 4.3v due to the duty cycle of the HD pulse. The HD pulse presumably would be something to sync with the video or on-screen text display. But it seems to display PAL video with no problem when it’s not in use, so unsure.

Really I’d just like it if someone can put my mind at ease on the subject. It doesn’t seem essential, but I’d like to know what it’s supposed to do.

Mirrored from The blog-hub for Peter "Sci" Turpin.

One of my brain-relaxing passtimes is to randomly browse ebay for interesting machines, broken items for spares/repair and so on. Like Thomas Edison said; “To invent, you need a good imagination and a pile of junk.”
Of course Edison didn’t have access to ebay or Google Image Search, so while I have a nice pile of junk, I can add a whole lot of extra random inspiration to it by just browsing images of junk.

One of my searches is usually for mill or lathe parts, to see if there’s any out there I could put to good use. I’ve been hoarding parts with the hope of building a mill or better milling accessory for my Conquest Lathe. Even a second-hand tiny mill will still run to well over £200, so my best chances of getting something within my tiny budget are:

1. Find a machine so broken it’s cheap, but damaged in such a way I alone can fix it at very little cost.
2. Find parts of other machines that I can assemble into a working milling machine.
3. Find a machine strange enough that few other people will bid on it.

Last week, Option 3 occurred on one of my browsing sessions. And I won it.

Small Homebuilt Milling Machine In need of attention to bring it up to a good standard the drive pulleys do not match exactly , although 2 or 3 speeds are available

there is play in the rise and fall of the headstock and a clearance problem with raising the head fully , maybe a bit of re-design needed!

the table has been fitted with a thrust Bearing and 1 end modified to accept a power feed unit but was never fitted

the table and / or the headstock needs a bit of shimming to get true machining

heavy fabricated steel construction with 370 Watt 1/2 Horse Power Single Phase 230 Volt Motor with Full Overload Protection and remote Stop/Start Pushbuttons

A good quality Cast Table , Size 475 x 154mm (Table cost was £100 ) 1/2″ MT2 Chuck with M10 Thread Drawbar Tilting Headsock ( left / right )

Adjustable Taper Bearing Headstock overall height of machine is 960mm depth is 600mm table to chuck height Max. 250mm Weight aprx 120 Kilos

Some light water marks to table due to garage roof leaking but not serious

please ask any questions i can e-mail more photos if required

£50 delivery on a pallet OR collection from Braughing , near Ware , Hertfordshire OR arrange your own collection

Mainland UK delivery only NOT to the Highlands or certain places in Wales,please ask

Payment by Paypal Only within 3 days of auction end

Happy Bidding!

A home made machine! Perfect!
Collection verses a £50 shipping fee would further lower competition, and it was just 30 miles north of me. And while I don’t want to offend the builder of it, the punctuation in the description probably doesn’t inspire the confidence for others to give that extra bid.

All in all, a prime listing for getting a bargain. And at £155 for 13,700cm³ of machining capacity, that’s a bargain in my books.

Now while I’m going to have to discuss the machines faults, I again don’t mean to offend the builder of it. It’s in my estimation the same sort of machine I’d have built in 18 months or so, with a few hundred quid in parts and the same development feel (initial planning, careful use, leading into jury-rigging just to get it finally working). So this machine has saved me a year and a half and a hundred quid or so. So I can skip straight into taking this messy but functional machine and refining it.

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Mirrored from The blog-hub for Peter "Sci" Turpin.