tanishqjain340 wrote this instructable detailing the build of his analog calculator project:
Do simple calculations with your math box.
The next time you need to crunch a couple of numbers, resist the urge to grab a digital calculator. Instead, round up some variable resistors, also known as potentiometers, and wire them into an analog mathematics rig. By twisting the potentiometers’ knobs and measuring the resulting voltage or resistance with a digital multimeter, you can perform simple multiplication and addition without a microprocessor in sight.
Go analog with a resistance-based calculator - [Link]
When you think Raspberry Pi and camera you probably already know the score; a small camera board that plugs into the Pi’s CSI connector fitted with a fixed-focus wide-angle lens. This versatile setup has been the basis of all sorts of homebrew applications. The SnapPiCam takes the Pi down a different route and converts it into a 5 MP digital camera with interchangeable lens.
Gregory L Holloway is the brains behind this idea, he developed it as an entry into an Instructables competition (which he won) and the response he got encouraged him to launch it on Kickstarter. The design uses the lower spec RPi A without an Ethernet port and with 256 MB of RAM. The camera includes a LiPo battery and DC-DC converter to make it truly portable and different versions allow you to add a rear touchscreen and various interchangeable, magnetic-mount lens ranging from wide-angle to telephoto zoom.
SnapPiCam, a DIY Digital Camera - [Link]
This video describes how a classic double-balanced diode-ring mixer operates. Very basic mixer theory is quickly reviewed, which describes how the sum and difference of the LO (local oscillator) and RF (Radio Frequency) inputs are generated at the IF (intermediate frequency) output. It is also noted that the sum and differences of the harmonics of the LO and RF are also present at the IF output. Math waveforms on the oscilloscope are used to illustrate the operation of the mixer, and the actual waveforms from the mixer are compared to the math waveforms and the differences are discussed. A detailed description of the operation of the mixer is presented, including the switching action of the diodes. Finally, the frequency components are are expected from the mixer are shown on the spectrum analyzer.
How a Diode Ring Mixer works | Mixer operation theory and measurement - [Link]
Dave explains a big trap in high frequency measurement with your oscilloscope. Based on a viewer request, Dave demonstrates how to incorrectly and then correctly measure the signal output level over frequency of your function generator using your oscilloscope. Some whiteboard transmission line theory is thrown in as well.
EEVblog #652 – Oscilloscope & Function Generator Measurement Trap - [Link]
New 200mm fans EBM-Papst will cool down your devices while not making a lot of noise.
Maybe you already belong to users of top-level fans from EBM-Papst. This time we bring you another hint for well-proven types – considerably powerful with a 200mm diameter. The types are:
● A2E200-AH38-01 – 9 blade fan with sickle-shaped steel blades, driven by a powerful motor M2E-068 BF with power of 64W/ 230V/ 50Hz. Maintenance-free ball bearings and a thermal protection contribute to a long lifetime of the fan. The motor requires to connect an external capacitor 1.5uF/400V. The fan is suitable for a continuous operation (S1) and it can be mounted in any position.
● W2E200-HK38-01 – 7 blade fan with a full round nozzle from an aluminium alloy and with same motor unit as above-mentioned type. The fan features a very easy installation – mechanically and also electrically, as it also contains a capacitor (1.5uF) assembled to a body of the fan. The fan is suitable for a continuous operation (S1) and it can be mounted in any position.
Naturally, these fans are universally usable not only for cooling of electric devices, but also in air conditioning (HVAC) and in food industry.
How do you cool in these hot days? - [Link]
If your design contains Microchip’s MCP79XXX series RTC chips and you are running into troubles using them, this technical brief is intended to resolve several of the commonly-asked questions regarding developing stand-alone serial interface real-time clock/ calendar devices with MCP79XXX. Similarly, there’s also another application note from Microchip which provides detail assistance and guidance in using these RTC devices.
Q&A concerning Microchip’s MCP79XXX RTC chips - [Link]
This Instructable describes building of a fun and very simple LED clock using Arduino that displays the time to the nearest half hour using LEDs.
Arduino LED clock - [Link]
Whether it´s necessary to operate a device in gloves, or you only wish the given push-button was sufficiently big and well visible, new series of round and square caps for series Multimec 5G will solve it.
Well known Dutch producer of top quality switches – company MEC, comes with novelties in a form of relatively big caps for a universal series of push buttons Multimec 5G (lifetime of 10 million cycles).
Series 5G is exceptional by the fact, that it can by equipped by a huge amount of caps of various sizes, shapes and colors. In result, you might even not say, that beneath so different push-buttons” (caps), still the same push-button switch is used.
The latest addition to the family of caps for the 5G push buttons is:
● 10R/10RF/10RM – round 30mm caps. 10R has a slightly curved surface, 10RF has a flat surface and sharp edges, and the 10RM has a metal plate with an illuminated legend.
● 10Q/10QM – square 22mm caps. 10Q has a flat surface, 10QM has a metal plate with a illuminated legend.
Multimec 5G push-buttons operate with these caps reliably – independently on the place of pressing the button (in the middle/ on the edge). Both series have optional accessory – sealing enabling to reach IP67 and a plastic spacer. Need for a spacer depends on the front panel thickness (into which a push-button is built-in) and on the overall design of a device. Overall building height is only 11mm and they´re intended to be placed in almost one level with a front panel, resulting in a very elegant look.
Homogenous illumination (backlight) of these big caps can be easily reached by means of 4 small LEDs placed on a PCB around a push-button. This also gives a possibility to freely use various LED according to your choice and to use their color combinations – for example for indication of a device status. As a standard, 7 solid colors are available and 1 transparent “frost ice” white for illumination.
Recently, we also added many other caps and push buttons from company MEC into our offer. All new additions can be found below this article.
New MEC switches can be seen even from afar - [Link]
This DIY digital clock plus thermometer is designed by Joe Farr and is based on PIC18F25K22 microcontroller. The complete construction details of this project including circuit diagrams, PCB layouts and PIC firmware are posted in his website. He developed his firmware using Proton PIC BASIC compiler, which is available for download for free for this particular PIC microcontroller. He uses DS1302 RTC for timekeeping and DS18B20 for temperature measurement. The temperature and time are displayed on four 2″ seven segment LED displays.
Another PIC-based digital thermometer and clock - [Link]
Project is based on Holteks IC HT7610A, which is a CMOS LSI chip designed for use in automatic PIR lamp, flash or buzzer control. It can operate in 3-wire configuration for relay applications. In our project we have used relay instead of Traic to connect any kind of load in output, HT7610B IC is suitable for traic and HT7610A for Relay application. The chip is equipped with operational amplifiers, a comparator, timer, a zero crossing detector, control circuit, a voltage regulator, a system oscillator, and an output timing oscillator.
Its PIR sensor detects infrared power variations induced by the motion of a human body and transforms it to a voltage variation. If the PIR output voltage variation conforms to the criteria (refer to the functional description), the lamp is turned on with an adjustable duration. The circuit doesnt required step down transformer and can work directly by applying 110V AC or 220V AC (Capacitor C7 needs to change for 220V AC (0.33uF/275V) and 110V AC (0.68uF/275V)
PIR Sensor - [Link]