This blog will keep to a simple theme of my tinkering with electronic and computer related toys, gadgets, projects and the like. I do hope from time to time there is something for someone to find when they are exploring these things for themselves. From an early age, I was always attracted to electronic gadgets an I continue to enjoy myself with my hobby. Unfortunately with a busy life, time becomes short an I can not indulge myself like in the past.
There are three elements to the Fiber Optics Kit: transmitter, fiber-optics cable, and receiver. The transmitter is made up of a diver and source. The source is a light-emitting-diode (LED). The driver is a circuit that changes the electrical signal into a form required by the source. The fiber-optic cable in this kit is a plastic optical cable (in high-end cables glass is used). The receiver is made up of two basic parts: the detector, and the output circuit. The detector converts the light received by the cable into an electrical signal. The output circuit amplifies, and if necessary, reshapes the electrical signal.
The Metal Detector Kit is a basic Oscillator. When the transistor is turned on, it sends a current into the inductor-capacitor circuit. The inductor is made up of the winding red coil. This inductor-capacitor circuit has a resonance frequency in the AM radio band. Part of the energy in the inductor-capacitor circuit is feed into the emitter of the transistor, amplifying the signal and causing the circuit to oscillate at the inductor-capacitor resonance frequency. Metal is detected, when the magnetic field of the coil, comes into the presence of metal. The magnetic field can move easier causing the inductor-capacitor circuit to oscillate at a lower frequency. The video below will demonstrate this idea.
The Pocket Dice Kit is made up of fourteen LEDs to represent two dice, and three main circuits: Clock Oscillator, Presettable Counter, and Decoder Circuit. There are seven LEDs per dice for the six possible dice combinations. To create a number on the dice (LEDs), a switch is pressed down, causing a short, and producing a number. The Clock Oscillator is an IC that consists of two NAND gates that are digital integrated circuits that inputs are tied together to form an inverter circuit. The frequency of the oscillation is about 60 cycles per second producing a square wave. By pressing the switch one causes a short and the feedback stops hence the oscillator halts. The Presettable Counter function are two IC. These two IC convert the square wave of the Clock Oscillator. Every time the clock puts out a pulse, the counter will change its output. The two counters convert the clock pulses in six combinations of "1" and "0". The Decoder Circuit takes the output of the Presettable Counter and lights the correct LEDs. It consists of a NAND gate and an OR gate.
The Lie Detector Kit is an oscillating circuit based on the theory that when one is lying there is a change in galvanic skin resistance that would cause the oscillator frequency to increase. This kit uses the IC 555, and one can change the sensitivity with a low and high switch and a in series trim pot. In operation, a person would hold a wire connected to washers in each hand. When the person is lying to a question there GSR changes causing the frequency to change or the sound to increase to indicate lying. In testing this theory I found that it did not work. Lastly, this kit can also be used as a moisture indicator, and in the video, I demonstrate that this idea is very promising.
This is Velleman's 3x3x3 LED light Cube uses a 9v battery; in addition, this is a programable LED light cube. Velleman recommends starting with this kit before assembling the there 5x5x5 LED Cube.
The Velleman's 3D LED Cube has 125 LED's that is controlled by two STP16CP05 integrated circuits, of which, are surface mounted devices. Other than mounting the two SMD IC, the 125 LED's proves to be the most tedious work. Velleman has a great video to show how to assemble the LED's properly . The Light Cube is programmable via USB A-male to B-male cable and software from Velleman's product support. The Light Cube comes with no USB cable, and no 9v power adapter. Below is a short video demonstrating the Light Cube.
This is the demonstration of the SR2C, AA7B, and Mono Power Amplifier. In this video, I try to adjust the transformers (T1 and T2) to tune into an AM frequency.
The AA7B is an antenna amplifier which will amplify radio frequency signals (HF, VHF, UHF). I'll use the AA7B with the SR2C in a future post for demonstration. The AA7B is connected by coaxial cable to the receiver. In addition, the AA7B can be powered by a 9V internal battery of external power supply. The AA7B is for boosting reception only; transmitting RF into the AA7B will damage the unit.
The Ramsey's SR2C is a single-conversion superheterodyne receiver designed for listening to AM broadcasting stations in the range of 4-19.5 MHZ. The SR2C does not come with an antenna or external speaker. In a future post, I will demonstrate the SRC2.
This is Kit 27 from Kitsrus a 1 Watt Mono Power (audio) Amplifier featuring Philips integrated circuit TDA 7052. I built this kit to modify a shortwave radio that will be featured in a future post the Ramsey's SR2C. This amplifier uses a 6-12 volt direct current power supply to drive up to a 8 ohms speaker. In the picture, I have a 8 ohm speaker, a 12VDC battery pack, and a mono plug attached; these items are add-ons and do not come with the kit.
I decided to sell my PanaVise 333 Rapid Assembly Circuit Board holder for the PanaVise 350 Multi-purpose unite. The 350 unite offers Ribbed, neoprene jaw pads and a self-centering 9-inch jaws. I did this because the 333 was too big for smaller PCB and did not allow me to work on the connections that were located at the edge of my PCB; more over, I could change out the vise with the 315 Circuit Board Holder (my preferred head for working a PCB). The 315 comes with a standard 12-inch cross bar, but, like me, one can buy bigger bars. I bought a 22 and 30-inch crossbar, and extra arms if I have two PCB on the bar at once. Lastly, I added the PanaVise 371 Solder Station, which is, a soldering iron holder, controlled solder wire feeder, and two sponges. The 371 is mounted with screws to the base of the vise. PanaVise for me is the best tool on the market for electronic hobbyist but PanaVise offers a wide selection of Vises and accessory's. In closing, I like to say that PanaVise offers the best customer service I have experienced. Thank you Cheri because you answered every question I had when I was putting together my vise.
PanaVise 350 Multi-purpose Work Center also a good shot of the 371 Solder Station.
PanaVisa with the 315 Circuit Board Holder good shot of the soldering iron holder and sponge.
This is an Infrared Spotlight on a 6x6 printed circuit board using six 100 ohm resistors and 36 IR light emitting diodes. The Spotlight requires a 12 VDC power-supply. In the pictures and video, the Spotlight did not illuminate or allow my camera to work in the dark, in other words, see in the dark . The Infrared Spotlight did seem to compliment my night owl scope with out using the scopes built-in IR. When I get the 12 volt battery pack, I can do a better assessment out of my work shop since I am tethered to my power supply currently. Some possible uses is as an IR-beckon, a complement to an IR-enabled device, or, possibly IR for a robot, but with the addition of IR light detectors.
The DT-100K is a great simple tool for testing Diodes and Transistors. I also like the throw back style of the DT-100K front panel's lay out. This tool allows one to identify if a Diode is in working order and the Cathode or Anode of the Diode; more over, the DT-100K will identify a NPN or a PNP Transistor and that the Transistor is working. In the video I test out the DT-100K. First, I test that the Diode testing functioning is working properly. I start by shorting the black and red leads together (this allows me to use the internal Diode in the test) and push in the test button. The alternating LEDs are a indication of a correct response. The last part of the Diode test is to connect a diode to the red and black leads. The two LEDs indicate which is the Cathode or Anode. The black lead out-put is the left LED and the red lead out-put is the right LED. The LED that lights indicates the Cathode side of the Diode. Second, I test the Transistor Operation, I short the yellow and black leads together and press the test button (shorting allows me to use the internal PNP or NPN Transistors in the DT-100K) then vary the base current with the knob and switch between the two Transistor types. The last part of the test I use a NPN-transistor. I do this test using the yellow test socket then with the green (emitter), yellow (base), and black (collector) leads. The only modification I had to make was to add four washers to the screws that hold in the front panel. If one uses just the screws, the panel will not stay secure because the heads are too small
First stage of assembly
Potentiometer connected with bare wire
Leads installed knots used to take pressure of solder to PCB
Connected Battery snap and Push button switch
Soldering the alligator clip
When having to solder to bare metal, it is helpful to use fine sand paper to scratch the metal, so the solder applies better.
Much like the last Substitution box the Model K-37 is easy to assemble. The resistance values are from 10 ohms to 1000k ohms or 1 meg ohm in 24 steps. A good tool for determining the desired resistance values in circuits under design or test. The video below show the testing out to make sure the knobs are in correct position.
Resisters through my magnifying lamb
Two knobs and switch upper center
The green jumper wires activate the knob based on the switch position
Assembled before adding front panel
Determining correct position for K ohm knob (right)
Determining correct position for the ohm knob (left)
The Elenco's Model K-38 Capacitance Substitution Box is a trouble shooting tool that can be used in repairs. For example, where a capacitor value is unknown or in new electronic designs that the capacitor value is aloof. The Capacitance values are from 100picoFarad to 0.1microFarad. The video below shows the test out of the substitution box using a Multimeter.
Finished
Capacitors, switches, and wires installed on the PCB
PCB back soldered capacitors, switches, and jumpers installed
This was a fast little gadget to assemble, which translates sound into light. Sound is taken in by a microphone and translated into light using four high-intensity LEDs. Sensitivity of the microphone can be adjusted using a potentiometer. This unit has practical use for the hearing-impaired, for example, to indicate a teleophone and doorbell ringing, or for the fun of it.
I had to put this project together in a rush; in addition, for use as a receiver for a AM and FM transmitter that I have yet to assemble. In the video, I am tuning the FM station with no test equipment and with the aid of a Voltage Meter. In the future, I plan to do a second assembly of this model with more details and properly tested with an Oscilloscope, Function Generator, and Voltage Meter. This was a fun project because one assembles the radio in modules. Again, I will do a more detailed check out with the second model. I just had not posted in a few months and wanted to let everyone know the blog is still alive.
