Upload

Loading icon Loading...

This video is unavailable.

How to Make a Simple Counter of a Calculator

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to like ChipDipvideo's video.

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to dislike ChipDipvideo's video.

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to add ChipDipvideo's video to your playlist.

Uploaded on Nov 30, 2010

How to Make a Simple Counter of a CalculatorWe often need a counter, for instance, to calculate the number of turns or hits. However, we don't always have one at hand. But there is always a way out. You can make a counter out of a calculator. In fact, it is quite easy. Let's take a calculator and disassemble it. We remove the screws. Then we need to access the pads under the keys. In this case we'll have to remove the plastic holders. However, usually these pads are attached by screws.Having done that, we find the first and the second contact of the equal sign. We solder wires to these contacts. Then we connect a magnetically operated reed relay to the wires. The reed relay will substitute the equal sign key. As a result we get a programmable counter. It can count not only whole numbers adding by one or two but also some other values.Let's clear the pads and cover them with flux. Now we tin them. We cover the wires with flux and then also tin them. Then we solder the wires.Now we straighten up the wires and close the body. It is not necessary to tighten it with screws. We close it till the catch clicks and that is enough. With the help of alligator clips we attach the reed relay to the wires. Now we can check how the counter works.But first we need to program it. We dial 1+1 and bring the magnet close to the reed relay several times. Now we can see that numbers on the screen are changing as the counter counts how many times we brought the magnet to the reed relay. For example, this time it's 14.This also works when we unwind a coil. If there are 500 turns we can unwind one at a time. With each turn the number on the screen will decrease by 1.The calculator can also count fractions. Let's assume that by winding a coil we increase its inductance by 0.73 millihenry. So we dial 0.73+0.73 and continue counting. In this way we don't count the number of turns but the inductance of the coil at this particular moment. At some point we will see, for instance, that its inductance has reached 6.57 millihenry. This is close to what we need and we can stop here.At the same time the calculator can still be used with its original function. It can still count, multiply and divide. But the wires on the equal sign allow us to use it in this unusual way.

Loading icon Loading...

Loading icon Loading...

Loading icon Loading...

The interactive transcript could not be loaded.

Loading icon Loading...

Loading icon Loading...

Ratings have been disabled for this video.
Rating is available when the video has been rented.
This feature is not available right now. Please try again later.

Loading icon Loading...

Loading...
Working...
to add this to Watch Later

Add to