While the LT3080-based PSU project is still ongoing, I had an immediate need for a workable unit for experiments related to my course work at Algonquin.
The YINHUA unit ($50 delivered via eBay) has so far performed reliably and is accurate enough for my current needs. Recommended.
A single LT3080 is capable of providing constant current and voltage.
Today my Linear Tech LT3080 LDO voltage regulator arrived in the mail. Will post an update once I get it breadboarded. Some fun ahead!
The results of my practice run tonight.
Tonight I took advantage of the milder temperatures and soldered a few SMT resistors onto a scrap PCB as practice. It went smoothly, with the exception of Q1, which hopped when I applied too much pressure while tacking it down. While it looks a bit goopy, it tests out alright. Still a bit too much solder on some of the Rs. Unfortunately I do not have any magnification other than my camera lens, so it’s hard to inspect my solder work in any great detail. Clicking on the photo above does offer a bit of zoom, however. Particularly pleased with R1. A definite improvement over my first attempts. Looking forward to more practice with finer pitch IC packages.
Power Supply Update
After watching Dave Jones’ 5-part lab power supply series, I’m beginning to grasp some analog circuit basics and am eager to try breadboarding my own constant current/voltage supply circuit. To help me design my own power supply unit, I’ve ordered IC samples, capacitors suitable for decoupling/noise reduction on the supply line and op amp bridges, and resistors with a suitable tolerance for the voltage shunt/current sense amp. I was able to scavenge two sturdy potentiometers from some old electronics to feed the op amps in setting the voltage and current levels. Other components, such as the 12-bit DAC, will allow a micro signal the op amps and adjust the current and voltage at a decent resolution (0 to 4096). Jones’ schematic shows two single-turn potentiometers accomplishing the same task.
Part one of a series produced by Dave Jones of EEV Blog where he covers the steps in designing a regulated variable lab power supply based on the LT3080 voltage regulator and LM334 current supply. This design is of interest as it is a simple design that allows for control by MCU. After looking at the commercially available units, I’ve decided that designing and building my own is the best route. This will allow me to include custom features like a display showing total current drawn by the load with min/max reading, as well as switches to turn the supply lead off without shutting down the entire power supply.