Kerry Wong has posted a detailed teardown and testing of a Reliable Electric 800W PureSine Inverter:
The last ingredient for my backup power project is an inverter. Since the battery bank I built is a 12V 1.5kWh one, an inverter that can handle a load between 500W and 1000W would be a suitable choice. In theory, all the lights and the refrigerator in my house consume just around 500W. So the 1.5kWh battery bank should be able to power all the essentials for at least a couple of hours in the event of a power failure.
I wanted a pure sine wave inverter as opposed to a modified sine wave inverter since many household appliances and electronics do not play well with modified sine wave inverters due to the high harmonic distortions. After some extensive research, I finally settled on this 12V 800W pure sine inverter made by a little known Chinese company Yueqing Reliable Electric Co. Ltd.
Teardown and repair of an Agilent E3632A DC power supply from The Signal Path:
In this episode Shahriar & Rosanah investigate an Agilent power supply which does not appear to power on. It can be quickly observed that the fuse has failed on the unit. Using an isolation transformer a small amount of AC voltage is applied to the unit after the fuse replacement. It is clear that a short is present somewhere in the instrument since even at 10V AC the instrument consumes more than 1A.
Kerry Wong did a teardown of Microsemi’s C900502 X-band planar 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.
Kerry Wong did a teardown of a Philips dimmable LED bulb:
One of the first things you will notice about this light bulb is that the compact construction. Most noticeably the lack of the telltale heatsink fins. As a result however, the heat dissipation capability is greatly sacrificed. During normal operation when mounted pointing downwards without any airflow obstruction, the case temperature raised to above 60°C within a few minutes. I could only imagine what the temperature would be like when the light bulb is mounted facing upwards in a semi-enclosed light fixture.
So I decided to take it apart to see the what the construction looks like inside.
Agilent 53152A 46GHz frequency counter teardown and repair from The Signal Path:
In this episode Shahriar investigates a faulty Agilent 53152A 46GHz frequency counter. The instrument does not power on and shows no sign of internal voltage presence. Teardown of the instrument reveals a large PCB where all analog and digital circuity is contained. The power supply module is a module components and upon measurements shows no activity.
The power supply is a simple switching architecture with functioning input rectifier and capacitor filter. By using an oscilloscope it is clear that the power supply PWM controller attempts to start. However, the main power supply pin shows unstable voltages indicating inadequate charge retention on the rectifying capacitor. Replacing the capacitor revives the startup condition and the power supply function returns. The PWM controller and main switching transistors are also replaced with new ones. After this repair the unit powers on and passes all self-tests. The unit can successfully measure signal frequencies and power.
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.
Since this is such a cheap meter, I wasn’t expecting much. But it actually feels really sturdy in hand and the construction looks reasonably solid, which is certainly a good start. It came with a nice little black pouch inside a non-descriptive cardboard box. It even includes a decent product manual.