Restoring an SLA battery one experiment

Around 2017m05d22 I pulled a 12V  SLA battery from a trailer.  The SLA was being used to power the emergency braking system for the trailer.  I did not know how old the battery was or when it was last charged.  Here is a photo of the battery.

My DMM  measured 6.3V across the SLA.  My experience says this means the battery is near death and cannot be restored.  I chose to mess with it anyway.  I put the battery on a 14.3V / 2A charger and measured a voltage of 13.9V.  This usually means the battery is not accepting charge and is presenting a high impedance to the charger.  I left the charger connected overnite.  The next day the voltage was still 13.9V.   I disconnected the charger and the voltage was 12.2V ...... this was a surprise.  I do not yet have an explanation for it.

I shorted the SLA with a spoon for 2 seconds and got a big spark and some glowing metal.  Afterward the voltage was still 12.2V.   With the charger connected the voltage was now 13V.

I will continue to monitor this battery.

Gus in Denver



tags:   99guspuppet  777SLA  777restoreSLA

48 LED Infrared Spotlight Schematic ... bought on eBay

This is the schematic for a spotlight available on eBay as of 2017m03d01 ....

Purchased qty 4 from eBay      ~ $3 each    with CdS photocell  12VDC

When dark , spotlight should turn on.  When dark , CdS in series with 345K resistor causes voltage to base of Q2 ( PNP ) to drop below voltage at emitter which is approximately 6v  ( using forward drop of IR LEDs as voltage reference )   ...Q2 turns on current flows into the base of Q3 ( NPN ) through a 1K resistor.     The emitter is tied to ground.  Q3 turns on and

Q1 is a power transistor that connects to 8 Strings of LEDs with a 27 ohm resistor in series in each string.  Q1 has a 2.2 ohm resistor between it’s ?? and ground.  This is used for current sensing.  

There are 11 resistors, 3 transistors , no capacitors , no inductors.  IRC can turn Spotlight on and off.

The coating on this PCB is very dark and hard to scratch ... so following the traces was difficult.

The 27 ohm resistors typically have 1V across them when the spotlight is on. This means 36 ma is flowing through each string or about 288 ma for 8 strings. the voltage across R3 is about 0.6V which is 272 ma. My DMM is a $5 cheapie .... so these readings are approximate.

  

I measured one diode chain as 11.66 VDC , 10.22 , 8.75 , 7.30 , 5.86 , 4.43 , R10 , 3.45 , 2.01 

tags:   #48IRLEDSpoghtlight   777IRLEDSpotlight             99guspuppet

Install HomeGenie on RPi3 2017February Success

This is the install procedure that worked for me .......  2017m02d17
I am using a RaspBerry Pi 3A with the Raspian OS version 8 on it.

I originally tried to use the instructions provided at the HomeGenie website.... no joy  .... I believe there were several typos in the instructions.

I used the terminal app that comes  as part of the Raspbian package.  I typed in the following commands.  Some of these commands take a long time to complete. ( over 10 minutes )

 sudo apt-get update

 sudo apt-get upgrade

 sudo apt-get install mono-runtime

 wget https://github.com/genielabs/HomeGenie/releases/download/v1.1-beta.525/homegenie-beta_1.1.r525_all.deb

sudo apt-get update

sudo apt-get install gdebi-core

sudo gdebi homegenie-beta_1.1.r525_all.deb

I have been using Class 10 SD cards ( both 8GB and 16 GB )

I want to thank the many people that I have gleaned information from off the internet.

99guspuppet

tags: 777homegenie 777homegenieInstall

Insulin Pen deconstruction disassembly How to hack

How to use a pen <== these links are not produced by me
http://www.diabeticlivingonline.com/medication/insulin/how-to-use-insulin-pen
https://www.youtube.com/watch?v=sv3C6Nl1VUc


I am fascinated  by these pens and how intricate they are.  They cost ~$70 retail and about $1 when paid for by insurance..... which is surely a scam of some sort.  I wanted to be able to reuse these pens .... reload them with insulin or black widow venom ( that last part is satire ) .

So far I have not had a brilliant idea of how to use these individual parts or how to refill the pen.



plastic melts very easily.  Ask me how I know.  I was using a small grinder.  Then I started using an Xacto blade.

rubber plunger ( orange ) slides in glass tube

blemish

There was a blemish here that I thought might pin some of the parts together , so I filed it.

tags:   777insulinPen    777insulin   777hack   777pen  99guspuppet