PDA-Based ETDs

[Farrell]

The idea crossed my mind. However, I think I need to build my prototype and make sure it works as envisioned first! Like I said before, I'll post in a week or two after I've built it and have done a few rounds on local pianos.

Terry Farrell
  ----- Original Message ----- 
  From: AlliedPianoCraft 
  To: Pianotech List 
  Sent: Thursday, May 01, 2008 12:18 PM
  Subject: Re: PDA-Based ETDs


  Terry, It seems to me you have it all down to a science. Why don't you make a few of them while you're at it. I'm certain you'll sell them here in a minute.

  Al Guecia



  From: Farrell 
  Sent: Thursday, May 01, 2008 10:33 AM
  To: Pianotech List 
  Subject: Re: PDA-Based ETDs


  Voltage Depression ("memory") occurs primarily in NiCad batteries 
  (nickel-cadmium). NiMH batteries are almost never affected and Li-Ion 
  batteries are NEVER affected. I have used numerous NiMH battery packs that I 
  have made up extensively on my bicycles for powering lighting systems with 
  consistently excellent results. I have tried Li-Ion and have had problems 
  with the electronics involved (not to say that Li-Ion is bad, but I've just 
  had problems with the technology). I have also used NiCad batteries in the 
  distant past - nothing short of a nightmare. NiMH for small packs are about 
  the same size as Li-Ion, seem to be bullet-proof, last forever (zillions of 
  recharge cycles) and cost half that of Li-Ion.

  I already have a 12V smart battery charger for NiMH, so that won't cost me 
  anything. And the voltage indicator, which is only $17 is an add-on - the 
  other $139 packs don't have one, so it is an upgrade and not comparable. 
  Truth be told, I do also have to incorporate a voltage reducer and current 
  limiter for proper charging and that cost me $13. So the pack and 
  electronics will cost me $26 plus the voltage monitor. Even if I had to buy 
  the charger, I can get a smart charger for that pack for $17. No battery 
  holder needed - the pack will be a pad for my PDA. So total cost if I had to 
  buy all the parts - batteries, charger and needed electronics - would be $13 
  + $13 + $17 = $43 and I chose to upgrade the pack with a battery monitor, so 
  add $17 for a total cost of $60.

  We're still talking less than 50% the cost of the other - and I get to have 
  all the fun of building it! And I do enjoy building battery packs. It's 
  kinda like doing key bushings - can't explain why I enjoy doing them so 
  much, but I do. So building the pack is just icing on the cake. The pack 
  will also likely have a Sitka Spruce panel to hold its shape!

  YMMV.

  Terry Farrell

  ----- Original Message ----- 
  From: "Don" <pianotuna at accesscomm.ca>
  > And the cost of the battery holder, and the cost of the voltage indicator,
  > and the cost of a charger, and what is your labor rate per hour? Lots more
  > than $13.00 I suspect. Plus LI vs Nickle Metal Hydride--no memory effect 
  > on
  > the LI, but there is for the Nickle.
  >
  > At 06:08 AM 5/1/2008 -0400, you wrote:
  >>Well, for one, I already ordered batteries to make up an external pack. 
  >>The
  >>pack I'm making is half the size of the Zap pack (and half the capacity -
  >>but still way plenty, I'm quite sure), and the batteries only cost $13
  >>compared to $139.
  >>
  >>Terry Farrell 


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