[chbot] Robotics Group meeting, 5 Idris Rd, 630pm, Monday 20 Nov 2023 report

[Mark Atherton]

Apologies for the lateness of delivery, I included everyone except the 
Robotics reflector on the list !

Regards, Mark

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Hello everyone,

Good turnout with 22 attendees, and lots of huddles-of tech-talk. $60 + 
change (in gold, and flat-money) collected and transferred into the 
robotics loose-change jar (for later banking).

All sales from the trading table should go into the brown box on the 
wall, and are directly for the benefit of our host club, Christchurch 
Amateur Radio Club, NZART Branch 05.

Equipment donations are welcome for the trading table, but no CRT based 
product, printers, toner or items that are likely to be a disposal burden.

With thanks on behalf of the group,

Mark Atherton

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Mark opened by talking about Idiot-proofing and ESD-proofing public 
exhibits. An initial simple N-CH source follower design was flawed. 
Changing to a P-CH topology improved the situation. Adding a shunt input 
capacitor further improved the design. There was a short discussion 
about mitigating ESD issues using a charge integrating capacitor.

This was followed by commentary on Li-Ion cell safety based on a FENZ 
report. Issues include physical damage to Li-Ion cells causing internal 
heating with possible escalation to battery-pack fires. Other issues 
include home-made power-walls using cells with different cathode 
material. Manufacturer cell data sheets do not generally include 
required information. See 
“Report_174_Lithium_Batteries_Whats_the_problem.pdf”

Andy Gardener then gave us an update on his EV adventures, including 
some significant structures he has assembled to allow EV batteries to be 
changed (relatively) easily.

William talked about his venture into incandescent seven-segment 
technology, with his Minitron digital speedo/tacho project.

Michael talked about (aircraft) ADSB receiver and FlightRadar24.com as 
well as latest updates to his his electric furnace. He has also built 
and outdoor light controlled by ESPhome.

Interesting material on YouTube :

Electric Racing Car, 0-100k in 900ms, with ground-effect, pulls 3.8G
www.youtube.com/watch?v=XQIu5tZ0vbQ
Do Petrol Heads become Lithium Heads ?

Crushing Huge Lithium Ion Batteries with Hydraulic Press, Hydraulic 
Press Channel
www.youtube.com/watch?v=t1j9TUV5coc

Old pinball machines are amazingly complex, Technology Connections
www.youtube.com/watch?v=ue-1JoJQaEg