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<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Thanks for the pointer William. Now investigating TVR diodes.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Cheers,
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">D<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Chchrobotics <chchrobotics-bounces@lists.ourshack.com>
<b>On Behalf Of </b>william fleete<br>
<b>Sent:</b> Friday, 8 November 2024 3:49 pm<br>
<b>To:</b> Christchurch Robotics <chchrobotics@lists.ourshack.com><br>
<b>Subject:</b> Re: [chbot] PCB Power Supply.<o:p></o:p></span></p>
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<p class="MsoNormal">I’ve started to use TVS diodes on anything remotely touching automotive power
<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"helveticaneue",serif;color:black">With input diode to knock out reverse spikes or reverse connection and self resetting fuse if the TVS shunts or shorts out.</span> and for 12v level signals in addition to a transistor,
buffer gates to somewhat isolate the 12v levels from logic level stuff. I did that on a clock I designed for my mum’s Honda which didn’t have a dash clock. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Fri, 8 Nov 2024 at 10:46, Martin Towers <<a href="mailto:tinytowers@xtra.co.nz">tinytowers@xtra.co.nz</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">I used to make gizmos for the car. They worked fine on the bench and<br>
blew up in the car. In a real car with a lead acid battery and<br>
alternator there are a lot of spikes and surges from all the inductive<br>
loads going on and off. Dirty battery contacts will blow things up.<br>
<br>
Since then things seem easier. Semiconductors are harder. The regulator<br>
xl1509 will survive up to 45V and that should be enough most of the<br>
time. There is reverse voltage protection.<br>
<br>
The CAN interface is just a conversion to the CAN dominant-recessive<br>
electrical system. You can use the ESP32 TWAI controller to monitor the<br>
CAN bus.<br>
<br>
So it's a good plan.<br>
<br>
Martin<br>
<br>
PS<br>
Let us know what colour the smoke is.<br>
<br>
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