Getting control over a 50 watt CO2 laser cutter from China

weekend-box

Unboxing laser cutter Co2 50 watt from China:

There are people around me who think I’m crazy. And they are probably right. Who else would buy a machine from someone he does not know. I have to pay upfront. It is not clear how things will get delivered, what gets delivered, or if it gets delivered at all. Up to the point I can lose the money I have spent. Best of all: that machine is dangerous enough to potentially kill me. And it has the potential to put my home on fire too. Well, that sounds like an exciting weekend project, or not?

See the full post at MCU on Eclipse homepage.

App note: Selecting a FET for use with the Si875x driver

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Another application note from Silicon Labs on determining the proper FET used on their Si875x driver based on its application. Link here (PDF)

The Si875x enables creating custom solid state relay (SSR) configurations. Supporting customer-selected external FETs, the Si875x combines robust isolation technology with a FET driver to form a complete, isolated, switch. Versatile inputs provide digital CMOS pin control (Si8751) or diode emulation (Si8752) to best suit the application, plus flexible outputs to support driving ac or dc load configurations. A floating secondary side dc voltage source is unnecessary as the product generates its own self contained gate drive output voltage, reducing cost, size, and complexity.

App note: Driving MOSFET and IGBT switches using the Si828x

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App note from Silicon Labs on their MOSFET and IGBT driver Si828x and how to determining its external components to achieve optimized performance. Link here (PDF)

The Si828x products integrate isolation, gate drivers, fault detection protection, and operational indicators into one package to drive IGBTs and MOSFETs as well as other gated power switch devices. Most Si828x products (except the Si8286) have three separate output pins to provide independent rise and fall time settings and low impedance clamping to suppress Miller voltage spikes. This application note provides guidance for selecting the external components necessary for operation of the driver. Although this application note discusses the topic of driving IGBTs and MOSFETs, users can apply the same concepts for driving other gate-based power switches, such as SiC (Silicon Carbide).

A look inside the DS3231 real-time clock

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Pete posted an article taking a closer look at Maxim’s DS3231 real-time clock:

Fortunately, Maxim also offers the DS3231, which is advertised as an “Extremely Accurate I2C-Integrated RTC/TCXO/Crystal”. This chip has the 32kHz crystal integrated into the package itself and uses a built-in temperature sensor to periodically measure the temperature of the crystal and, by switching different internal capacitors in and out of the crystal circuit, can precisely adjust its frequency so it remains constant. It’s specified to keep time within 2ppm from 0°C to +40°C, and 3.5ppm from -40°C to +85°C, which means the clock would only drift 63 and 110 seconds per year, respectively. Very cool.

See the full post at HeyPete.com blog.

Teardown and repair of an Agilent 53152A 46GHz microwave frequency counter

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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.

More details at The Signal Path.

Check out the video after the break.

MickMake Mail #15: EspressoBin, FireBeetle, UDOO x86, ArduShield // News

Another mailbag with lots of interesting stuff. EspressoBin, FireBeetle, UDOO x86, ArduShield, nRF52832 and an extra thank you from one of my Patrons.   If you like this YouTube channel please subscribe by clicking the in-video button, or the little Continue reading MickMake Mail #15: EspressoBin, FireBeetle, UDOO x86, ArduShield // News

Posted by The Man on MickMake - Live. Learn. Make.

Build a talking Alarm Clock synced to Google calendars. // Tutorial

My original project 30 years ago was to build a talking Alarm Clock, which was based on a 6502. This is a revamp of that project. Interesting to see what can be done so easily these days! The old clock Continue reading Build a talking Alarm Clock synced to Google calendars. // Tutorial

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