Difference between revisions of "Zappy Module"

From Hackstrich
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== Project Status ==
 
== Project Status ==
 +
* 2015-03-26: Sent to OSH Park for PCB manufacturing. Still need to order main transformer from Coilcraft and parts from Digikey.
 
* 2015-03-15: Completed routing board, silkscreen and checklist run done. Waiting 24h for final review and submission to OSH Park.
 
* 2015-03-15: Completed routing board, silkscreen and checklist run done. Waiting 24h for final review and submission to OSH Park.
 
* 2015-03-08: Finished schematic and BOM, checklisted.
 
* 2015-03-08: Finished schematic and BOM, checklisted.

Revision as of 18:50, 27 March 2015

Zappy Module is a board-level module that takes control input via some kind of protocol and outputs signals to zap someone like shock collars do.

Project Status

  • 2015-03-26: Sent to OSH Park for PCB manufacturing. Still need to order main transformer from Coilcraft and parts from Digikey.
  • 2015-03-15: Completed routing board, silkscreen and checklist run done. Waiting 24h for final review and submission to OSH Park.
  • 2015-03-08: Finished schematic and BOM, checklisted.
  • 2015-03-07: Started putting schematic and BOM together.
  • 2015-02-02: Started putting together overall circuit idea.
  • 2015-02-01: SPICEd out some ideas.
  • 2015-01-29: Captured waveforms of all output levels.
  • 2015-01-05: Arranged to borrow a shock collar to characterize the output of it.
  • 2013-05: Started throwing ideas around.

Overview

  • Main control input via I2C
  • ARM signal must be high before zapping is allowed
  • Two trigger pin inputs, can program levels for each via I2C then zap with simple "pull pin high" I/O

Theory of Operation

  • Input voltage from 3-9V is stepped up to 10V using a boost converter (AZ34063U) to get the intermediary voltage rail
  • MCU controls a FET that charges a cap from that rail via a series resistor to control charge rate
    • Divider on the cap feeds into an analog pin on the MCU, once the analog pin reaches the desired level the MCU shuts the FET off again
  • Once cap is charged, MCU pulses a FET that dumps the charge on the cap through a 1:100 (or so) transformer and to the output
    • 0.1-1kV should be achievable via timing the charge FET
  • May need a dump resistor if the cap is charged and needs to be discharged without zapping?
    • Could use the series charging resistor w/ a different FET to dump the cap through it?
    • Don't think this will be required, the charge cycle will only take ~1mS so it will be done right before the trigger, so the cap will never remain charged for long

Collar Reversing Waveforms

  • All collar output waveforms are through a 1/3 divider, so multiply by 3 to get actual amplitude
  • Lowest level (1L) seems to be ~90Vpp, highest seems to be ~450Vpp
    • I thought the highest was ~2x that? Need to measure the higher ones again to double check