HF2 – 24V Variable DC Power Supply

許風二號

Hui Gardens HF2 24V variable DC power supply prototype is meant to power small electronics from hobby 3V3 and 5V sensors (e.g., Arduino and Raspberry Pi) to 24V industrial process 4-20mA transmitters. Housed in its own Pelican 1200 case, it can withstand rough transport and handling. It takes AC or DC input from an external source up to 30V AC/DC and outputs a rectified lower DC voltage. The input is a 2.1mm barrel jack that should be easy to find at an electronics parts store.

Due to the experimental intended purpose of this DC power supply, a 0.5A breaker is put in place instead of a fuse that requires replacement.

Hui Gardens HF2 features a 2W potentiometer for adjusting voltage output which should be plenty even when powering 4-20mA transmitters. Since it relies on setting of voltage via your multimeter prior to use, it is as accurate as your multimeter and there is nothing to calibrate.

The output comes via a binding post, so you can use banana plugs or bare wires. A standard spaced red and black post was chosen so that the fancy integrated two conductor leads can be used as well.

The red toggle switch cover and badge of Chairman Mao is the pièce de résistance taking this variable DC power supply to a new level.

Specification Value
Maximum Voltage Input 30V
Maximum Voltage Output 24V
Maximum Current 0.5A

DECOMMISSIONED

This working prototype had been superceded by the Hui Gardens HFX electrical test set

3D Printed Battery Cover for IS33

Seeing a good deal of customers with broken or missing battery covers for their Crystal IS33 pressure calibrators, I thought there must be a less expensive option of just getting the lid. This was my first crack at 3D printing and all the fun aspects it entails. Took me three tries, but the current version fits perfectly. Due to the tight dimensional tolerances, I don’t think PLA would be feasible and SLS with Nylon 12 aka PA 2200 looks to fit the bill.

Learn more about the 3D printed battery cover for IS33 pressure calibrator

HCal

I created HCal in my spare time as a tool to help me organize test equipment that I deal with. After years of trying my hand as a calibration technician, I realized that people often needed a way to be reminded of when their tools are due for calibration. HCal is a free and simple way to get emails of such alerts no matter which cal lab you use, so that all your reminders are in one place.

Check it at https://huigardens.com/hcal