Modifying a 4S 100A LiFePO4 BMS Module

For those who are following my YouTube channel, you would know that I am in the process of building a high capacity battery bank. When this project is done, I plan to use it with a 12V inverter as my backup generator in the event of a power failure. For the battery bank, I used eighty 3.2V 5.5Ah 32650 lithium iron phosphate (LiFePO4) batteries. These are arranged into 4 groups in series and each group consists of 20 cells paralleled together forming a 12.6V 110Ah battery bank.
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Teardown and Experiments with a Doppler Microwave Transceiver

I got a couple of Microsemi’s C900502 10.525 GHz X-band Doppler radar motion sensors a while ago. This batch was made in UK and had “UK patents 2243495 and/or 2253108 apply” printed on the case. I have seen a teardown of an HB100 Doppler radar module before and was wondering if I this one is any different inside.
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Teardown of a Philips Dimmable LED Bulb

I bought six Philips dimmable LED bulbs for my dinning room chandelier last year. These are 45W incandescent equivalent (7W, 450 lm 2700K) and are supposed to provide years of trouble-free illuminations. Over the course of a year of light use however, they all exhibited the same failure mode at some point of time. Two months in, the first bulb failed. The bulb would initially turn on, but after a few minutes it would turn off by itself. If the power is recycled the light can be turned back on again but only for a short period of time, and the cycle continues.
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Converting Celsius to Fahrenheit – The Analog Way

I have an old Keithley 1301 temperature probe. This probe is an accessory to the Keithley 130A/131 multimeter and is capable of measuring temperatures between -55°C to 150 °C. Since it outputs an analog voltage linearly proportional to the temperature (1mV/°C), it can be used with any multimeter that has a mV range.
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More Information on BSide ACM03 Plus Clamp Meter

In my previous post, I did a review and teardown of a cheap BSide ACM03 Plus clamp meter and concluded that it was a surprisingly good meter despite a few minor annoyances.
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BSide ACM03 Plus Clamp Meter Review and Teardown

I recently purchased a BSide ACM03 Plus clamp meter so that I could do some high current measurements for my tab welder project. This meter can be bought on eBay for around $25, which makes it one of the cheapest Hall effect clamp meters on the market that is capable of measuring both AC and DC current.
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Battery Adapter Teardown and Sony A6000 Power-Off Current Draw

I bought a Sony A6000 mirrorless digital camera last year to replace my Cannon PowerShot Elph 300 HS point and shoot camera for my YouTube videos. While its fast auto focusing capabilities is great for my teardown and project videos, the A6000 also has some drawbacks. Namely, you cannot shoot video while the camera is hooked to the charger or computer via the USB port. And because of this limitation, continuous shooting could be a challenge as the battery would be depleted rather quickly.
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Building a Single Pixel Scanner

A flat bed scanner typically uses three rows of CCD sensors (RGB) to capture images placed directly on top of the glass bed. When the CCD array scans from one end of the image to the other, the digitized color image is formed. So with a similar approach, we could use just one photosensitive device to capture the entire image one pixel at a time via raster scanning. Now that I have an HP 7044A X-Y recorder I could use it’s X/Y servo mechanism with a suitable sensor to build a single pixel scanner.
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ESD Mat For My Workbench

I just bought an ESD mat for my workbench. ESD mat is great when working with sensitive electronics components as it safely dissipates any charge built-up to the ground via its dissipative surface through the attached grounding wire.
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Dual Purpose Spot Welder With Pulse Duration Control

I had wanted to make a spot welder for a while. Most of the DIY spot welders use a momentary switch the primary side of the microwave oven transformer (MOT). Due to the simplicity of this design, it is very simple to make. This design however, has some inherent safety issues as the momentary switch is typically within reaching distance of the operator (unless a foot switch is used) and inadequate insulation could increase electric shock risk. Further more, the current flowing through the primary winding can significantly exceed the current rating of the switch and cause the switch to fail. Due to the inductive nature of the winding, the switch can sometimes arc over and pose significant risk to the operator.
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Reverse Engineering a Uniden Cordlessphone LCD

I recently upgraded my home phone system and thus was left with a couple of old Uniden DCT648-2 handsets. Most of the components inside are probably not salvageable but these handsets use 3×16 character LCDs, so it would be nice if I could reuse them in my other projects.
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Wavetek 395 Timebase Upgrade

I got a Wavetek 395 arbitrary waveform generator (AWG) last year. Unlike my other equipment (such as HP 8566B, HP 5350B, HP 8642B and Racal Dana 1992) which all came with high stability ovenized crystal oscillators, the Wavetek 395 only comes with a 100ppm crystal. While the stock timebase is perfectly fine for all but the most serious measurements, I decided to upgrade it to an oven controlled crystal oscillator (OCXO) as I happen to have a Vectron CO-717B58N lying around.
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HP 7044A X-Y Recorder Teardown, Lorenz Attractor

I picked up an HP 7044A X-Y recorder on eBay recently. This one was made in the early 1980’s and by today’s technology standard it is rather ancient. And because of this, it is very easy to interface with as the input is completely analog. My plan was to do some experiments down the road using the X-Y movements capability of this HP recorder.
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Cheap UV EPROM Eraser Teardown and Spectrum Analysis

Till recently, I have been using custom circuitry whenever I needed to backup some firmware. But the process was rather tedious as for each kind of EPROM or EEPROM I needed to study the protocol and timing requirements and then come up with the required circuitry on a breadboard. And wiring can easily become an issue with a high pin-count chip. So I finally got myself a proper EPROM programmer (it’s a TL866A) along with a $15 generic UV EPROM eraser so I could program EPROM/EEPROM’s quickly. While it was fun to build a programmer circuit each time, I think the effort can be put into something more useful.
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Beats Solo Bluetooth Headphone Teardown

I got this broken Beats Solo2 BT wireless headphone from one of my colleagues. In fact, it was broken once before around two years ago and I fixed it for him back then. The issue was because of a broken signal wire due to repeated flexing of the collapsible headphone band. This time around though, I am not going to fix it although I suspect that the cause remains the same. In fact, quite a few of my friends with the same Beats headphones had experienced similar problems. So I wanted to take it apart and take a closer look inside. A video of this teardown can be found towards the end of this post.
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