Tech on PCB Isolation

London Good Delivery Bar Ingot Mold – Design Drawings

Sat, 11 Mar 2023 00:00:00 +0000

London Good Delivery Bars define standards for gold and silver ingots. These are usually the ingots you see in movies. This post contains drawings I created for molds made from 1/4″ (6mm) mild steel.

Below you’ll find a pdf with the dimensions.

Your browser does not support embedded PDFs. Download the PDF instead.

See the creation of the molds below:

Waterproof, Sound Proof Generator Enclosure

Sat, 14 Aug 2021 00:00:00 +0000

For RVs and vans, generators are very useful but very loud. I wanted an enclosure that is both waterproof and noise dampening. It’s hard to find something like this, because it’s not easy to encase an engine and keep it cool.

In the end, I failed to keep the generator cool enough to for more than 2 hours.

I used a Wen 56235i generator. It is a cheaper variant of the Honda EU2200 series.

Integrate Zooz ZEN34 with Home Assistant

Sat, 26 Jun 2021 00:00:00 +0000

This overviews adding a Zooz ZEN34 smart switch to Home Assistant and using it to trigger automations.

This guide was written for HA 2021.6.6.

Prerequisites

Home Assistant
Z-Wave USB Hub
- I recommend either the Aeotec Z-Stick 7 or Z-Stick 5.
Z-Wave JS integration on Home Assistant
- See setup instructions here.
Zooz ZEN34 Smart Wireless Z-Wave Switch

Add ZEN34 to Z-WaveJS

Remove paper battery tabs from switch to power on switch
Login to Home Assistant
Go to Z-Wave JS and press “Add/Remove Device”

Repairing and Adding Bluetooth to an 80’s – 90’s AC Delco Radio

Wed, 17 Jun 2020 00:00:00 +0000

AC Delco Model 16131355

This post details the repair of a early 1991 AC Delco stereo. AC Delco made many variants of this stereo for both Chevrolet and GM cars, trucks, and vans from the early 80’s to the mid-90’s. While many of the stereos have more or less features (cassette players, radio presets, etc), the amplifier section of the radio is fairly standard and unchanged.

Internal Pinout and Schematic

Swapping LEDs and PCB in a Dimmable Nightlight

Mon, 11 May 2020 00:00:00 +0000

I’ve looked and been unsuccessful in finding household nightlights that meet my criteria:

auto on/off
dimmable
1800K CCT
decent CRI
uniform illumination
no flickering
power efficient

The closest I found was this nightlight. I like everything about it except the 3000K CCT. I believe it’s a bit too cool for a nightlight.

I ended up swapping the 3000K LEDs for 2200K LEDs. I would have preferred 1800K, but was unable to source them on Digikey.

Octopart API Pricing Scheme

Thu, 06 Jun 2019 00:00:00 +0000

Octopart, the search engine for electronic and industrial parts, doesn’t post the pricing for their API on their website. There’s a bit of irony, since Octopart scrapes pricing from sites like Digikey, who also tries to hide their pricing.

The Octopart API is a great resource for pricing BOMs. KiCost is a great example of tool that uses the Octopart API (although KiCost has moved away from Octopart due to the paywall).

As of June 2019, the Octopart API is as follows:

How To Spot a Counterfeit or Refurbished Motorola Razr V3

Thu, 04 Apr 2019 00:00:00 +0000

Note - There are many versions of the Motorola Razr, each with subtle differences. Even similar version have differences between countries. Not all of the differences of this counterfeit/refurbished Razr will apply to your Razr!

This applies specifically to the Motorola Razr V3, but you can find similar discrepancies on a Razr V2 or V3i.

If you have a feeling the phone is fake, that’s a good indicator that it is.

Motorola Razr V3: Real vs Counterfeit Teardown

Sun, 31 Mar 2019 00:00:00 +0000

Left- Authentic Razr V3, Right - Counterfeit Razr V3

I recently bought a Razr V3 on eBay. The listing below shows that it is made by Motorola. The pictures are of an authentic Razr. However I received a counterfeit Razr.

PS - I wrote a quick guide on spotting counterfeit Motorola Razr V3’s (without disassembly).

If the phone would have worked, I wouldn’t have cared. But it wouldn’t get a signal with my SIM, so I complained and got a refund.