<div dir="ltr">The LEDs themselves should not be causing interference. What is probably causing the interference is the buck mode converter which takes the higher battery voltage and reduces it to the LED's voltage while increasing the current, to achieve relatively high efficiencies. These use inductors and rapidly switching transistors. If you can put up with higher battery current drains and some localised heating, then you can use linear regulators which don't have these switching elements and therefore don't radiate.<div>Ferrite beads can be effective at keeping RF where it belongs - the tighter around the wires and the longer the better. If you are prepared to solder onto the circuit board, some strategically placed low value (100s of pF) capacitors can help. (It helps to know the transmitter frequency to choose the best values for the task.)</div><div>Not all LED lights even use regulators. Some of the cheaper ones with multiple small LEDs just have a series resistor, and these should also be quiet.</div><div>I hope this helps</div><div>Trevor</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jun 26, 2019 at 10:43 AM Bevin Brett <<a href="mailto:bevin_brett@hotmail.com">bevin_brett@hotmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div dir="auto">Talking to my daughter who is involved in kiwi conservation. They track, find kiwi using small transmitters on the bird leg and the teams carry a directional receiver with About a one metre antenna
<div dir="auto"><br>
</div>
<div dir="auto">But they can't use LED lights at night because of interference. </div>
<div dir="auto"><br>
</div>
<div dir="auto">How easy would it be to shield a normal commercial head lamp?</div>
<div dir="auto"><br>
</div>
<div dir="auto">Wrap it in alfoil? Small metal mesh? Mesh with some trivial circuit?</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Jun 17, 2019 11:00 PM, <a href="mailto:chchrobotics-request@lists.ourshack.com" target="_blank">chchrobotics-request@lists.ourshack.com</a> wrote:<br type="attribution">
<blockquote class="gmail-m_-4681944267343632738quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<p dir="ltr">Send Chchrobotics mailing list submissions to<br>
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<p dir="ltr">When replying, please edit your Subject line so it is more specific<br>
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<p dir="ltr">Today's Topics:</p>
<p dir="ltr"> 1. Sipeed MAix BiT for RISC-V AI+IoT - Seeed Studio (Synco Reynders)<br>
2. Robotics Group meeting, Monday 17 June 2019, 630pm, 5 Idris<br>
Road (Mark Atherton)<br>
</p>
<p dir="ltr">----------------------------------------------------------------------</p>
<p dir="ltr">Message: 1<br>
Date: Mon, 17 Jun 2019 21:58:00 +1200<br>
From: Synco Reynders <<a href="mailto:synco.reynders@gmail.com" target="_blank">synco.reynders@gmail.com</a>><br>
To: Christchurch Robotics <<a href="mailto:chchrobotics@lists.linuxnut.co.nz" target="_blank">chchrobotics@lists.linuxnut.co.nz</a>><br>
Subject: [chbot] Sipeed MAix BiT for RISC-V AI+IoT - Seeed Studio<br>
Message-ID:<br>
<CAKNOA8J=<a href="mailto:UrmPOjVwfwNP2rSkEMrbngRt-6-cTCTMUUuk098ogg@mail.gmail.com" target="_blank">UrmPOjVwfwNP2rSkEMrbngRt-6-cTCTMUUuk098ogg@mail.gmail.com</a>><br>
Content-Type: text/plain; charset="utf-8"</p>
<p dir="ltr">Here is the link to where I bought the board...<br>
<a href="https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.seeedstudio.com%2FSipeed-MAix-BiT-for-RISC-V-AI-IoT-1-p-2873.html&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=LhJuCO%2BfUC%2FicknxuIrv0qAXU8fsIgi8qLqWfAAKGqg%3D&reserved=0" target="_blank">https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.seeedstudio.com%2FSipeed-MAix-BiT-for-RISC-V-AI-IoT-1-p-2873.html&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=LhJuCO%2BfUC%2FicknxuIrv0qAXU8fsIgi8qLqWfAAKGqg%3D&reserved=0</a></p>
<p dir="ltr">Data sheet for the K210<br>
<a href="https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26source%3Dweb%26rct%3Dj%26url%3Dhttps%3A%2F%2Fs3.cn-north-1.amazonaws.com.cn%2Fdl.kendryte.com%2Fdocuments%2Fkendryte_datasheet_20181011163248_en.pdf%26ved%3D2ahUKEwiW-PPrjPDiAhW96nMBHRBbAecQFjABegQIBxAB%26usg%3DAOvVaw3CVZJWXlKkFgXPVCf8L4Ts%26cshid%3D1560765344956&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=YtKt%2FRVCAZVXedlQd9dOBnCe13RRwBaBAQrCjHelSu8%3D&reserved=0" target="_blank">https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26source%3Dweb%26rct%3Dj%26url%3Dhttps%3A%2F%2Fs3.cn-north-1.amazonaws.com.cn%2Fdl.kendryte.com%2Fdocuments%2Fkendryte_datasheet_20181011163248_en.pdf%26ved%3D2ahUKEwiW-PPrjPDiAhW96nMBHRBbAecQFjABegQIBxAB%26usg%3DAOvVaw3CVZJWXlKkFgXPVCf8L4Ts%26cshid%3D1560765344956&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=YtKt%2FRVCAZVXedlQd9dOBnCe13RRwBaBAQrCjHelSu8%3D&reserved=0</a><br>
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<p dir="ltr">------------------------------</p>
<p dir="ltr">Message: 2<br>
Date: Mon, 17 Jun 2019 22:01:46 +1200<br>
From: Mark Atherton <<a href="mailto:markaren1@xtra.co.nz" target="_blank">markaren1@xtra.co.nz</a>><br>
To: Christchurch Robotics <<a href="mailto:chchrobotics@lists.linuxnut.co.nz" target="_blank">chchrobotics@lists.linuxnut.co.nz</a>><br>
Cc: Ian MacPherson <<a href="mailto:ian@macpherson.gen.nz" target="_blank">ian@macpherson.gen.nz</a>>, Rory Deans<br>
<<a href="mailto:rory1@xtra.co.nz" target="_blank">rory1@xtra.co.nz</a>><br>
Subject: [chbot] Robotics Group meeting, Monday 17 June 2019, 630pm, 5<br>
Idris Road<br>
Message-ID: <<a href="mailto:6d4a8ac1-ad6c-fd28-1197-0fa30423c467@xtra.co.nz" target="_blank">6d4a8ac1-ad6c-fd28-1197-0fa30423c467@xtra.co.nz</a>><br>
Content-Type: text/plain; charset=utf-8; format=flowed</p>
<p dir="ltr">Hello everyone,</p>
<p dir="ltr">Enthusiastic turnout with 20 attendees, and lots of huddles-of <br>
tech-talk. $28 + change (in gold, and flat-money) collected and <br>
transferred into the robotics loose-change jar (for later banking).</p>
<p dir="ltr">Quick reminder: equipment donations are welcome for the trading table,
<br>
but no products that are likely to be a disposal burden such as <br>
printers, toner or similar. All sales from the trading table should go <br>
into the brown box on the wall, and are directly for the benefit of our <br>
host club, NZART Branch 05.</p>
<p dir="ltr">With thanks on behalf of the group,</p>
<p dir="ltr">Mark Atherton</p>
<p dir="ltr">============</p>
<p dir="ltr">Bevin brought along a soviet mechanical calculator to talk about as well
<br>
as quite a photographic tour of one of his latest mechanical calculator <br>
repair projects. Challenges include trying to drift out a (possibly cold <br>
welded) taper pin. All in all, quite a mission…</p>
<p dir="ltr">William brought in a homemade intercom using old telephones. Controller
<br>
is based around an Arduino Nano. Nice recycling project.</p>
<p dir="ltr">Peter Harris talked about switched mode power supplies, more <br>
specifically a battery management system for a home-made wall-of-power. <br>
Quite a discussion ensued around how to spread load across ten high <br>
voltage constant-current sources.</p>
<p dir="ltr">Synco talked about a tiny 64 bit image recognition module. This US$21
<br>
module includes VGA camera, a small LCD display and a CPU module. The <br>
main rub is that the CPU is RISC-V based running at 800MHz, with masses <br>
of I/O. The unit is configurable using a small FPGA, and is running a <br>
port of a micro-python wrapper controlling an embedded image-processing <br>
package.</p>
<p dir="ltr">Andy Gardner talked about his +-100kV volt meter !<br>
<br>
<br>
<br>
</p>
<p dir="ltr">------------------------------</p>
<p dir="ltr">Subject: Digest Footer</p>
<p dir="ltr">_______________________________________________<br>
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Meetings usually 3rd Monday each month. See <a href="https://eur04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fkiwibots.org&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=Bg2lYcFqAA%2F5JrV6Cmwih2gwTM7G5c%2BbWGJ%2FayDtDzU%3D&reserved=0" target="_blank">https://eur04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fkiwibots.org&data=02%7C01%7C%7C9de3110e1bff46b5abc008d6f312f8d3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636963660150070012&sdata=Bg2lYcFqAA%2F5JrV6Cmwih2gwTM7G5c%2BbWGJ%2FayDtDzU%3D&reserved=0</a>
for venue, directions and dates.<br>
Please edit your Subject line to reflect new subjects. </p>
<p dir="ltr">------------------------------</p>
<p dir="ltr">End of Chchrobotics Digest, Vol 141, Issue 4<br>
********************************************<br>
</p>
</blockquote>
</div>
<br>
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When replying, please edit your Subject line to reflect new subjects.</blockquote></div>