[Open_electroporator] Culture Shock, the open electroporator is a go

[William Beeson]

By logistically, I mean how will we actually pre-order and distribute the
early prototypes.

On Tue, Jun 14, 2016 at 10:20 PM, William Beeson <beesonwt at gmail.com> wrote:

> Logistically how will this work and is this email chain different from the
> other one?  I've been pretty swamped with other obligations lately, but am
> very interested in this pre-ordering and testing one.
>
> On Mon, Jun 13, 2016 at 1:13 PM, Keoni Gandall <koeng101 at gmail.com> wrote:
>
>> Looks great! I am excited to test the machine out.
>>
>> On Mon, Jun 13, 2016 at 2:13 PM, John Griessen <john at industromatic.com>
>> wrote:
>>
>>> Thanks to Bryan Bishop I will be developing an electroporator
>>> as in the attached proposal starting Wednesday, (and a little setting up
>>> Q&A with suppliers today).  Here's the feature list from the proposal:
>>>
>>> Programming will be via  USB device endpoint for serial ports, and
>>> referencing micropython documentation, plus a quick how-to published on
>>> kitmatic.com under the product docs section.
>>>
>>> Power will be by 28 Volt “wall wart” external UL listed power supply.
>>>
>>> Output zaps will be disabled when USB is plugged in – no USB remote
>>> controlling, (safety reasons).
>>>
>>> Programmability of output zaps will be by a sequence of python commands
>>> that do not guarantee a definite pulse shape.   Pulse shape will have to be
>>> arrived at by trial and error, using external observations with
>>> oscilloscopes to a voltage divided down test point that is inherently not
>>> safe to touch, and the whole oscilloscope is not safe when using it to
>>> observe the HV discharges. The reason it is not safe is the voltage divider
>>> chain of resistors could fail conductive-→oscilloscope gets zapped-→people
>>> touching oscilloscope usually.
>>>
>>> Micropython running on a STM32F030CCT6 which costs only $1.30 or
>>> STM32F401CBU6 which costs $2.8 will power the sequence and control
>>> functions.
>>>
>>> Indicator LEDs and pushbuttons will be provided for Ready, High, Medium
>>> and Low states of the machine.  The Ready LED will be red or green and when
>>> red, pushing Ready button “gets it ready” for the next zap.  High, Medium
>>> and Low  pushbuttons change to different stored zap profiles named  High,
>>> Medium and Low.
>>>
>>> Fire button causes a discharge.
>>>
>>> Batt indicator LED is low duty cycle blinking red when battery needs
>>> charging soon.
>>>
>>> Standard electroporation cuvettes with aluminum contacts will be
>>> connected somehow to the zap output such that high voltage cannot jump a
>>> gap to  to where the cuvette mounts when a safety guard is removed for
>>> loading and unloading cuvettes by hands.  The safety guard lid will
>>> probably operate like a knife switch where contacts, are more than 7mm
>>> apart and are bridged by a copper strip, (or pogo pins),  when the lid is
>>> pushed on.  When the lid is open, no bare contacts will have high voltage
>>> on them.  Bare metal with HV might be present inside a 3mm hole that a pogo
>>> pin goes into, or inside a 1.5mm insulated slot that a copper strip goes
>>> into to make contact.  Fingers randomly touching the cuvette area would not
>>> touch anything but insulator and have an air gap to HV of more than 7mm.
>>>
>>> The overall size will be less than 10cm X 10cm X 5cm tall if using
>>> electroporation cuvettes, and smaller if using pipectrodes.
>>> local LiFePO4 battery, circuits to charge it,  detect state of charge.
>>>
>>> Flyback switching power supply with  flyback 57:1 transformer  to
>>> generate at least 3kV into a 30kOhm load starting from the low 3.2V of the
>>> LiFePO4 battery, or the 28VDC external power supply.
>>>
>>> 28VDC external power supply (from AC 120V). Either/or a 28VDC external
>>> power supply (from AC 240V).
>>>
>>> John Griessen
>>>
>>> _______________________________________________
>>> open_electroporator mailing list
>>> open_electroporator at cibolo.us
>>> http://cibolo.us/mailman/listinfo/open_electroporator
>>>
>>>
>>
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>>
>
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