The OPT301 is in a TO-99 8 lead package and has good sensitivity but a reduced bandwidth of 4kHz. The peak response is just into the Infra Red region at 750nm but its sensitivity in the visible red spectrum at 670nm is only a few percent down. The circuit is almost identical to the original receiver. Changes are the new detector / PCB layout and i
Click here to download the full size of the above Circuit.
mproved op-amps. It uses a single supply at 12 - 13. 8V. The detector has a a 10M Ohm feedback resistor soldered directly betw1een pins 2 and 5. The detector output is followed by a NE5534 low noise op-amp (3. 4nV/Hz) which is configured as a bandpass filter. The final NE5534 is an inverting buffer amplifier with a gain of 20. The complete detector assembly is designed to be mounted in a small metal box at the focal point of a lens. The track is viewed from the top or component side. The detector is fitted to the other side of the board where a groundplane in unetched copper has holes countersunk for the TO-99 package. With a single supply line the body of the detector is held at the zener voltage. Therefore it should be isolated from the groundplane and from any metal enclosure. To evaluate the op-amp section I connected a 600 Ohm sig gen to the input of the bandpass filter and measured the response at the output of the buffer. The Input was adjusted from 50Hz to 3kHz with a constant level of 200mV Peak to Peak. As you can see from the results below, the 6dB bandwidth is just 200Hz. This makes the detector ideal for transmitters using modulated CW on a fixed frequency. My TX uses a 4MHz crystal and a CMOS 4060 oscillator / divider to generate 488Hz. This degree of accuracy gives the option of using a lap top and modern DSP softw1are (e. g. ARGO or Spectran by IK2PHD) to receive signals 20dB below normal noise level.
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: