Fate or not, first portable calibrator which I purchase as used for my tests at ITTSB Blog this is TIME ELECTRONICS LTD - MICRO CAL 1030 Precision analogue voltage current DC source (9-2010).
Product datasheet mentioning an AC power block which I never got, because interesting enough this was optional accessory.
Six years later (10/2016) ITTSB Blog established direct communication with Time Electronics UK (brand) and headquarters.
TE marketing team acknowledged the work of ITTSB Blog over the years and it did offer to me modern samples of their products for a product review.
And this is how one modern 1048 Voltage Current Loop calibrator with digital screen and digital controls is now property of my Blog.
Unfortunately the history repeated it self once more time, AC power block (12VDC) for 1048 calibrator this was again optional.
Due the fact that both calibrators are quite useful in my hands, for some time I was thinking to make then both to operate with DCV power supply instead using batteries.
Few months ago one friend of my, he made me a gift and this is analog blood pressure device of 80s.
By removing the analogue meter from it housing, I made the discovery that 1048 portable calibrator this has exact dimensions!
My next thought was to add on-board power supply this delivering 12V for the 1048 and also 9V for MICRO CAL 1030, so to be able to use both simultaneously.
Hart of the power supply become one regular transformer at 18V AC 700mA. Rectifier Bridge and filter delivers 22V peak which feed LM7812 this mounted over a huge aluminum plate.
Output of LM7812 after a second filter this is delivered to a power plug and also to a LM7809 this act as power supply for MICRO CAL 1030.
While total power supply design this is quite simple, finalizing of this project it required allot of work and time, everything it should fit in the dimensions’ of the specific housing (project box), and I had to do several changes and modifications.
The outcome this is now very impressive and unique as product design worldwide.
They say one picture equals 1000 words, I did add much more than one pictures.
I feel extremely proud about this project, because now long term calibration stability tests are now possible, especially for tests that I am going to do near soon at bench top multimeters.
Within 2019, ITTSB blog will receive several samples for a product review.