Upgrade the TL-21 Test Lead (DE-5000 LCR Meter)

I have 6 multimeters. A couple of them very good, others are simply good or just for simple checks like "is this battery dead?". Some of them can measure capacitors, but none of them are able to measure inductors or measure important parameters of these components, such as ESR (Equivalent Series Resistance) or Q factor, among others.

For this reason, after spending some time reading reviews and searching, I decided and purchased a DE-5000 LCR meter with some accessories. This is what I consider sufficient for my needs, and it seems to do a pretty good job for a fair amount of money.

One thing I do not like (I'm not the only one) is the length of the TL-21 test lead wires, something like 4 centimeters. I decided to improve it with a pair of long Kelvin alligator clip cables and in this post I show how to make such modification.

Battery Life Calculator: Theory and Java Software

When faced with the design of a battery-powered device the first question we must answer is: How much the batteries will last?

The answer to the above question determines how often the battery will need to be replaced, and even allows you to distinguish a viable design or product from one that is not. Suppose you have installed a couple of thousand sensors and some time later you find out that the batteries last only a couple of weeks. Congratulations, you've just messed up your life.

For a device with only one consumption state (constant current consumption) this is relativelly straight forward, but for devices with multiple consumption states it is not.

In this post I present how to estimate battery life and a JavaFX software to not only obtain the battery life given different consumption states of a device, but also to evaluate how much a variation of one of the two parameters (time or current) of each state will affect the battery life.

Schmitt Trigger Switch Debouncer (Briot Tracer)

In a recent post I've explained how I repaired a faulty Briot Tracer. One of the faults, despite not being directly related to the switch debouncer circuitry, required the reverse engineer of it to study if the signal was reaching the microprocessor correctly.

As the switch debouncer used in the Tracer is not the basic or classic Schmitt trigger circuit, it makes sense to take a moment to analyze it. In this post I will explain how this circuit works and it's differences with a conventional Schmitt trigger debouncer.

Reverse Engineering the Briot Tracer: Hardware II

In the post Reverse Engineering the Briot Tracer: Hardware I promised to post a hierarchical schematic of the Briot Tracer. The time has come.

You can find in this post the complete hierarchical schematic in PDF as well as the Kicad project, have fun!.

Reverse Engineering the Briot Tracer: Hardware

While I was repairing a Briot Tracer, certain sections of the main PCB circuit were reverse engineered. Mostly the power supply and the circuits associated with the debouncers of the rotary switches. Some time later the scanner broke again, this time the fault was not obvious and to try to find the problem it was necessary to reverse engineer other parts of the circuit. While I was waiting for an IC to arrive I took the opportunity to do a complete reverse engineering of the whole system.

In this entry I will share the complete schematic of the Briot Tracer.

Repairing a Faulty Briot Tracer

Some time ago I was asked to take a look to a machine from an optical laboratory with a non trivial type of fault to solve: an intermittent fault in a machine with moving parts. It is a thermal problem? It is a unstable solder? It is a bad cable?

I will show the problem encountered and how I'd solved it. In future entries I will share more information reverse engineering about the Briot Tracer, stay nearby.