Tenma 72 7750 manual

Could not load branches. Could not load tags. Latest commit. Git stats 14 commits. Failed to load latest commit information. View code. If you have Python on your system, you shouldn't have to install anything.

I developed this software for the TENMA but I assume most similar multimeters output the identical serial format, so I expect this software will work for multiple meters. Serial Notes I lost half a day because I couldn't figure out how to get Python to read these serial values. MIT License. Releases No releases published. Packages 0 No packages published.

General Specifications. Accuracy Specifications. DC Voltage. AC Voltage. DC Current. AC Current. Previous Page. Next Page. Multimeter Tenma Manual 21 pages. III V and double insulation. Do not use the Meter if it is damaged or the case or part of the case is removed. DC Direct Current. AC or DC. Double Insulated. Deficiency of Built-In Battery. Continuity Test. Capacitance Test. Refer to the Operating Manual. Conforms to Standards of European Union.

Set the rotary switch to an appropriate measurement position in A range. When the synthesizer was set to various frequencies, the multimeter followed it to the digit! Check out the pics of it in action, comparing the LCD screen frequency with that being displayed on the meter:. I also took a closer look at the PC interface. When I looked closely, I noticed it wasn't an electrical connection - it was an optical one! It has a phototransistor on one end, and a serial connection on the other.

I'm no stranger to tossing data around with light I made something that did this here , which was later featured on Hack-A-Day here. I wondered what the format of the data was, when to my surprise I saw it spelled out in the product manual!

Go Tenma! It should be trivial with python, pySerial, numpy, and matplotlib. Clearly I'm no stranger to graphing things in python :. How does the photo-transistor work without power? I attached my o-scope to the pins and saw nothing when RS mode was activated on the multimeter. Presumably, the phototransistor requires a voltage source albeit low current to operate. With a little digging on the internet, I realized that the serial port can source power.

I probably previously overlooked this because serial devices were a little before my time, but consider serial mice: they must have been supplied power! Joseph Sullivan has a cool write-up on a project which allowed him to achieve bidirectional optical laser communication over and completely powered by a serial port. Sure enough, there were bursts of easy-to-decode RS data.

Here's the scheme Joseph came up with to power his laser communication system, which presumably is similar to the one in the multi-meter.