From centech, to... this:

[Valhad]

Still working out a couple details, trying to get the process simplified for others to duplicate. However, I wanted to show off.

This is currently the state of my centech pinpointer. Once I've got it nailed down a full walkthrough/tutorial will be created with pictures and parts lists. Right now I'd estimate it's at about $10 in parts, with $3 being the metal on/off switch...

Enjoy!



Edit: I suppose I could have said what I was showing off!!! This is a 30 second video showing my new range-detecting feature on my centech pinpointer.

Edit: Walkthrough has been added! See page three of this thread.

[Jardue]

Looks good.

[badgerd]

I'm working on duplicating now... I think my scavenged transducer is toast though.

Did the range seem improved? From your video you're getting 2-3 inches and I generally get 1 max.

Can you PM me the specs for the transducer you used?

[forfun]

Will be looking forward to a write-up. Giving some thought to silent intensity indication. May put a small meter on it, or a led voltage indicator.

[Valhad]

Originally Posted by forfun

Will be looking forward to a write-up. Giving some thought to silent intensity indication. May put a small meter on it, or a led voltage indicator.

My current design would make a meter tricky, but I'd think a true meter might be hard to read/see while you were using it anyhow. A blinking LED should be pretty trivial, though. Heck, you could use the stock one with relative ease.

badgerd, I never did order a transducer. I ended up using an inline capacitor to restrict the DC and hooking up a little beeper from a defunct keyfinder. I'll send you the details. I still think we can improve on this if we can get the resistor values right in the timing circuit.

Valhad

[forfun]

For the range feature, does it get louder, change pitch, or vibrate faster?

[dogpound]

i gained a couple inches of depth outa mine by just tweeking the internal sensitivity pot

[chopz54]

Looks really good.

We dont have the Cen-Techs over here, but I guess the mods could be added to other pinpointers also??

[WildDigger]

That is awesome!!!!

[Valhad]

Originally Posted by forfun

For the range feature, does it get louder, change pitch, or vibrate faster?

On a basic level, it delivers a series of pulses, which get faster the closer the target is. Hooked up to a little noisemaker / speaker this translates into the clicks getting faster and making a slight pitch change. I haven't tried hooking it up to a motor yet in it's current configuration. The pulses need a little work still, to get them to a more useful duration and spacing. Might be able to drive a motor off it when it's fully complete, but I'm just not sure at this point.

Originally Posted by dogpound

i gained a couple inches of depth outa mine by just tweeking the internal sensitivity pot

^^^ This. Playing with the internal sensitivity dial can increase the range on most of these up to at least 2"-3" inches, it seems like.

[forfun]

The vibrator motor from a cell phone will run off the existing speaker circuit. Frankly it uses a lot of battery. This is the display I have in mind instead of a speaker, buzzer or vibrating motor.
http://www.youtube.com/watch?v=q-1zz53VBI0
But maybe what would be better would be intensity or speed of flashing of the led, rather than color based voltage.
I have ramped up the pot as well as taping a washer on the barrel so that it is on the verge of triggering. This gives max sensitivity of several inches.

[badgerd]

To reduce the battery drain from the motor you could use a limiting resistor... reduce the current draw from the 100ma or so (that's the draw from the cell phone motor I have been using) to around 50 or so. When I get home I'll find the value but I remember someone mentioning it... probably in the sticky at the top of this section of the forum.

I had one set up that way and it's been 2 months of digging at least 3 days a week (except last week...) and no battery change yet.

[dogpound]

i added a resistor on my micro vibrating motor, battery life on mine seems about the same as it would be normally, i just cut the speaker and tapped off of that. at first i had both the speaker & vibration but grew sick of the speaker and just did away with it.

[badgerd]

^^^What he said^^^

[dogpound]

by the way i used a 33 ohm, 1/2 watt resistor

[Briman05]

see i would get that pin pointer but one i have none of those tools and 2 i don't think i would know how to do that

[dogpound]

Originally Posted by Briman05

see i would get that pin pointer but one i have none of those tools and 2 i don't think i would know how to do that

its very simple, the only real tool ya need is a soldering iron and wire cutter. just snip the speaker wires and solder in the vibrating motor with a resistor inline on the red wire, add some heat shrink tube for looks and heat that up with a ligher and your done......very easy, its also just as easy to replace the power switch when it goes bad. for 16 bucks and about 5 bucks in mods ya can't beat those cen-tecs for the price

[forfun]

I spliced the motor parallel to the speaker. Not that good of a idea. I'll be adding the resistor you wrote about and disconnecting the speaker. Might substitute the speaker with a 1/8" jack instead. RS makes a momentary or a on / off switch that fits exactly where the oem one is. It requires no case modification. Just a additional lock washer inside.

[badgerd]

The "speaker" is not a speaker and you won't get audio from a 1/8 jack. It's a piezo buzzer that uses voltage to produce sound.

I added the motor with resistor to the piezo cap with no issues and had both working at the same time. The piezo was a little quieter and I had vibe too...

[forfun]

I was unaware that it was a buzzer. So, Yes, no audio in this case assuming it is self driven. I presently have both the buzzer and vibrating motor working, but it seems to have low volume and the motor runs slower. Not enough vibe if you are wearing heavy gloves
I use a 1/8" adapter for isolation ear buds on my F2. There is a 1/4" socket and a audio signal..