I made two small circuits today for temperature control of the extruder head on a reprap type 3D printer. The idea is to control the temperature, which needs to be somewhere between 200 and 240 C I think, using EMC2 and two parallel port pins. The first circuit is based on the 555 and produces … Continue reading Temperature control circuits
Update: this version of the component may compile on 10.04LTS without errors/warnings: frequency2temperature.comp (thanks to jepler!) There's been some interest in my 2-wire temperature PID control from 2010. It uses one parallel port pin for a PWM-heater, and another connected to a 555-timer for temperature measurement. I didn't document the circuits very well, but they … Continue reading Temperature PID control - Part Deux
We hooked up the temperature measurement circuit and the PWM-amplifier to EMC today and tested PID-control of the extruder head temperature. The ini, hal, and xml files for this are here: temp_control_pid.tar It's probably much easier to figure out the connections from the diagram below than to browse the text files. The square wave, which … Continue reading Temperature PID control
Curing epoxy mouldings typically requires elevated temperatures (+ 40Â to 70 C) for 4-12 h. Previously we have done this in a cardboard box with a car-heater continuously blowing hot air into the box. By adjusting the number and size of holes in the box the temperature can be crudely varied. Here's an attempt to create … Continue reading Temp controller for curing box
We've put together a few of these butterfly laser-diode mount + driver combos. It combines a heat-sinked butterfly mounted laser-diode with a current/temperature controller by Wavelength Electronics. The assembly is low enough to fit into a 1U (~44 mm) high 19" rack-enclosure. The 14-pin laser-package (yellow) is held in place by ZIF clamps/sockets 5253-100-07S (standard) and … Continue reading Butterfly laser diode mount
I've been assembling and testing this PCB over the past few days: It's a linear +/-2 A voltage-to-current amplifier meant for driving a constant current through a Thermoelectric Cooler (TEC). The circuit is (loosely) based on a 2001 Burr-Brown/TI application note "SBEA001 - Optoelectronics Circuit Collection". Description: U1 drives one half of the H-bridge (Q1 … Continue reading TEC-Drive prototype
I made this aluminium bit on the lathe/mill today. It holds a blue laser-module from dealextreme. The brass barrel measured about 11.81 to 11.84 mm in diameter so I first drilled a 10mm hole, then opened it up slowly on the lathe until the module just fit the hole. There is an M3 set-screw to … Continue reading TEC mount for laser-module
Here's an experiment I've done recently: (Time-lapse of ca 18 hour experiment. Bottom left is a spectrum-analyzer view of the beat-note signal. Top left is a frequency counter reading of the beat-note. Bottom right is a screen showing the a camera-view of the output-beam from the resonator) This is a measurement of the thermal expansion … Continue reading Measuring the thermal expansion of ULE glass
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This page lists my Open Hardware electronics designs. Most newer designs have KiCad schematic, PCB-layout, and gerber-files available. Please ask if you are interested in the older designs - some may be available. ADA4898 LNA Low noise preamplifier, AC-coupled 0.1 Hz to 1 MHz. Input-referred voltage noise is well below 50R resistor at room temperature … Continue reading Open Hardware