For several years my Mom has been in a Nursing Home with Parkinson's disease. As she has lost function of her muscles I have attempted to use technology to assist her. I have posted a couple of my attempts to assist her in my Blog on E-14. h...
Tonight I am experimenting with an LTC 6992 Voltage Controlled PWM IC. I had an application where I wanted to control a motor's speed using a variable voltage and the LTC6992 came up in my search. Here is the chip as listed on the Newark site:&nb...
While digging through my stores of old and obsolete parts I came across this 3.5 X 2.5 X 1.25 cm black box with 4 leads and no markings. I can remember it being in my stock of parts back in the late 1960s and early 1970s when I was repairi...
Earlier this summer my son-in-law John and daughter found themselves with a bad problem in the basement of their home. Tree roots had gotten into the sewer main leading from their home and one day the water stopped draining. Unfortunately the water b...
I frequently work on circuit boards from Dental Equipment. Since these circuit boards are often used in wet or humid environments the manufacturers like to coat the boards in a thick layer of epoxy or other hard sealant. Probing these boards has alwa...
I am studying the similarities and differences in the circuits of these Switch Mode Power Supplies from a 5 Volt, 6 Volt, and 12 Volts wall warts. I want to find out how they create their output voltages and how they regulate these voltag...
Tonight I salvaged a Maxim ICL 7662 Voltage Converter from a circuit board that came out of a piece of dental equipment called a Cavitron. As I glanced over the data sheet on this little IC I was immediately captured by its simplicity of design and a...
For nearly all of my life a lot of my most treasured possessions (Electronics) have been in my shop in the basement of one home or another. Many of the houses have had less than desirable foundations and as such I have had my share of moisture and ev...
When I passed the junk pile at my son's dental repair business today I noticed an old Ritter Meteor X-Ray unit sitting in parts. It was slated to go for scrap metal the next day. The one item that caught my eye immediately was a small Variac moun...
Back Ground Information: One of the important tools in the modern dental clinic is a fairly strong and concentrated light source which is used to cure (harden) light-activated resins. After placing the malleable plastic resin where it is needed ...
There have been all aspects of technology discussed on the E-14 Forum but I have never seen any mention of the rather impressive growth in the technology that is being incorporated into Greeting Cards. This technology was evident the other day when I...
A while back on the recommendation of jancumps I purchased a ZD-985 Desoldering station. I have been extremely happy with this purchase and even contracted with the vendor to upgrade their basic Chinese translated owners manual. There has, however, b...
Tonight an older Dental Electro-surgery Unit was sent to me for repair. The dentist uses an Electro-Surgery unit like a scalpel to remove growths from inside the mouth and also to cauterize areas of tissue. The hand piece has a chuck and will a...
In my latest box of circuit board goodies I came across this interesting circuit that has helped revolutionize dentistry. However, before I get into the function of the board itself, let me digress and give you some back ground on its appl...
Tonight I am going to describe the repurposing of a power supply board from an obsolete dental X-ray machine. Before I start, however, I want to digress and go back 60 years to the beginnings of my interest and enjoyment of electronics. The man ...
Today son Mike, 4ringfan , brought me a box of circuit boards that he had salvaged from out-of-service dental equipment. One of my favorite pastimes is studying an unknown circuit board to see if I can figure it out and find any potentially usable ci...
Many of the small electronic gadgets that I use daily, cameras, labeler, and test equipment, do not tolerate battery voltages below 1.4 volts. As a result I have always quickly accumulated a lot of AA batteries with voltages around this level. When I...
Once again I am playing with an IC I dug out of an old piece of equipment. Today it is the Texas Instrument TL 494 Pulse-Width-Modulation Control Circuit. The Data Sheet: http://www.farnell.com/datasheets/1962656.pdf which indicates that it...
