# Tagged Questions

A device or circuit that generates an AC signal at a certain frequency.

361 views

### 3 phase computer chip

I have just had a conversation with a friend who studied quantum computing. Sadly I have forgotten most of the conversation as it was far beyond my knowledge threshold. Essentially he was saying was ...
334 views

### Setting the internal oscillator speed on PIC12F1822

I'm trying to get a PIC12F1822 to run at 32 MHz. Here are the relevant bits of code: ...
198 views

### Voltage Controlled Oscillators

I want to know how to calculate the gain of a VCO. I've looked online and see that there exists a formula $$K_{VCO} = \dfrac{f_1-f_2}{V_1-V_2}$$ but it would seem that this result would give ...
2k views

### Problem with a Relaxation Oscillator (using Op Amp)

I'm studying a relaxation oscillator. This wikipedia circuit shows exactly my circuit with the only difference that I'm using different values for each resistor. I called resistor R the one ...
235 views

### Why does this PUT oscillator max out at about 25 Hz?

I'm a beginner working through the Make: Electonics book, and I got to the circuit that uses a PUT to create an oscillator. Here as image of the circuit: The voltage builds at the red arrow until ...
1k views

### Crystal Oscillator with OP AMP, or Oscillator circuit built with Crystal and Op Amp

I've been trying to make a Oscillator circuit with a Op Amp and an crystal (7.68 MHz) Similar to the one in the schematic below, but for a 7.68 MHz crystal. Is this possible? (it says low freq ...
898 views

### Make the oscillator choice

I am using a PIC24FJ128GA010 and I need to make an oscillator choice. If I am not wrong, two main oscillator could be used 32KHz and 8 MHz. 1. Do I really need 32KHz oscillator? 2. Element 14 website ...
3k views

### Crystals, Oscillators, and Resonators. What the difference?

I am trying to figure out the difference between crystals, oscillators, and resonators. I'm starting to grasp it but I still have some questions. From my understanding, an oscillator is built from a ...
2k views

### How do I use a quartz crystal in an oscillator?

How can I get a quartz crystal to make square waves at 4.096MHz? So far I have the 4.096MHz quartz crystal and this schematic I saw: Where can you find an amplifier with a single input and what ...
473 views

Is it possible to make a 20 MHz radio with this by creating a circuit consisting of a battery, that crystal oscillator and an antenna?
315 views

### Standalone MLCK generation for I2S

I'm looking at switching a rough hardware design from using a master-IC generated MCLK signal for I2S to using a standalone MCLK generator circuit. I'm a bit new to this area of electronics, but from ...
542 views

### Design for an analogue oscillator that doesn't drift in frequency?

VCOs (Voltage Controlled Oscillators) in analogue music synthesizers are notorious for drifting with temperature. What design solutions are there for an analogue audio VCO that keeps close (as in ...
129 views

### Testing Oscillator Over Temperature

I want to characterize the frequency inaccuracy of several silicon oscillators over temperature to see which one will work best in my end application. If I populate the oscillator on a bare-board and ...
267 views

### Broken 32kHz Oscillator

I am trying to build a simple 32kHz crystal oscillator but I am seeing something strange. I am using a simple circuit in that the crystal is in feedback around a current starved inverter. However, I ...
691 views

### Stabilizing opamps - am i doing it right?

I'm designing a high current linear regulator and learning about real opamps as opposed to ideal ones described in tutorials all over the net as i go. My initial voltage regulation design was ...
193 views

### Is using a shorter timer period less accurate than using a longer one?

I'm using a dsPIC 33FJ128GP804 and I'm trying to record data at 200 Hz as accurately as possible. My device also has a GPS and I'm noticing that my timer is drifting compared to the GPS by about 333 ...
307 views

### Synchronise crystal oscillator with external short burst

I am trying to generate a stable 4.43361875 MHz clock (i.e. PAL colourburst) synchronised to the colourburst of a PAL video signal. In a PAL signal the colourburst is provided for only about 8-10 ...
1k views

### Four transistor/full bridge version of the Royer oscillator

For some time now, I have been trying to figure out what (in theory) would be the most efficient way transfer power across a transformer. Applications include high voltage power supplies and induction ...
650 views

### Building a UHF FM audio transmitter

I'd like to build a UHF (~800 MHz) FM audio transmitter. I have no experience in electrical engineering but I study physics and I'd like to acquire practical experience in electronics. In fact my goal ...
2k views

### PIC keeps resetting: Am I seeing side-effects from breadboard use?

I'm using PIC18F4680 and am having problems running it form a 40 MHz external clock source or 10 MHz crystal in HSPLL mode. Using 10 MHz crystal in HS mode seems to be fine and 5 MHz crystal in HSPLL ...
213 views

### Cheap high speed oscillator [closed]

What is the fastest oscillator I can build for less than \$1 in parts ? Further specifications: SMT only Pricing for Quantity 1000 Stable frequency Sine wave preferable I don't care too much what ...
3k views

### How to configure the internal oscillator in a PIC16F616?

I want to use the internal oscillator in PIC16F616 in 8 MHz configuration and have the I/O function on RA4 and RA5. I've read ...
938 views

### Sharing an oscillator between two ICs

I have a microcontroller and an FPGA on the same board. If they're both going to run at the same clock speed, can I just use one oscillator to clock them both? There seems like there is something I ...
3k views

### Using the ATMega328 with the internal oscillator?

I have a project that I think would be best suited for an ATMega328P. However, in every simple project I've seen, people always hook up a 16MHz external oscillator. From what I can see, it should have ...
2k views

### High-stability oscillators (non-crystal)

Are there any high-stability oscilators, which are not crystal based, given that temperature is stable down to 0.01 C and voltage down to 0.001V? Will LC-based oscillator be able to show performance ...
360 views

### Oscillator Driven LED - Not Oscillating

I have an IR LED which is switched at a rate of 32.768kHz from an oscillator circuit (relevant portion shown below). I have 10 prototype PCBs. 30% of them work while the others don't. The problem is ...
162 views

### How do you output a frequency/note with a 1V octave keyboard controller?

To be specific, I made this: from here And to test the CV output, I used this schematic: from here It works as a oscillator. Every time I hit a key it will oscillate at that note, but it wont ...
393 views

### Unstable oscillator using dsPIC

I've built up a small PCB with a dsPIC33FJ128GP804 microcontroller and a 7.3728 MHz crystal, among other components. While testing it last night I had no problems at all getting it working. It fired ...
385 views

### dsPIC 30F2020 Primary Oscillator

What exactly is the Primary Oscillator in the dsPIC 30F2020? How accurate is it? How does it compare with the Internal Fast RC Oscillator (FRC) on the same device? (I know this is more than 1 ...
889 views

### My 12 MHz crystal does not oscillate

I am having trouble with a board I have had fabricated. The processor is an NXP LPC1788 Cortex-M3. I am using a 12 MHz external crystal to clock the processor as recommended in the datasheet. ...
695 views

### How to control a speaker

We are trying to produce a sound wave with speaker. We also need to be able to control the frequency (we don't have specific numbers, about 50-500Hz). As far as we are concerned we are looking for a ...
162 views

### Symmetric voltage oscillator

How do I create an oscillating output (around 50 to 80 MHz) with both negative and positive voltage (parallel)? I have got already a 48 MHz oscillator, but I don't mind about replacing it if it's ...
248 views

### Where is the oscilator in the 555 chip provided here?

I have tried a while to understand how the 555 chip is built, I opened the datasheet of TI available here : http://www.ti.com/lit/ds/symlink/lm555.pdf anyway this is the scematic from the datasheet ...
98 views

### What kind of signals can a frequency synthesizer like this generate?

Take this chip as an example: http://www.maxim-ic.com/datasheet/index.mvp/id/3491. It says that the frequency range is 8.1kHz to 133MHz on the main output and 8.2MHz to 133MHz on the reference ...
448 views

### How to generate HF AC from a DC source?

UPDATE After reading comments, I realize that I need to ask better questions. Here is a more explicit question. Ignore the original, which is below for reference. I am driving an LED. The idea is to ...
634 views

### How does this flasher circuit work?

I was watching the video on Forever Flasher circuit in Advent Calendar of Circuits 2011 series by vk2zay. Below is the circuit I am talking about. However, there are some things I understand and most ...
413 views

### Applying an oscillation to a DC voltage?

I've lost a 555 IC that I had owned, so thought I'd make an relaxation oscillator for practise out of an operational amplifier: The example of the simulator I have been using creates a square wave ...
2k views

### Op Amp based Hartley oscillator

I would like to build an oscillator that will satisfy a few requirements. The main requirement is to have exactly one capacitor. Another one is to have high Q and sine wave output. I am considering ...
367 views

### Clock Shape Changes with Two O-Scope Probes

I have a Max V CPLD development board which has a 10MHz oscillator onboard. I hooked up CH2 probe to the output pin and then wrote a small VHDL program that output the clock to an external pin. I ...
2k views

### Problems with Wien Bridge oscillator circuit simulation in Mutisim

I am trying to build a Wien bridge oscillator that oscillates at 2.1kHz and that can be switched on by a transistor. The reason for me placing a transistor switch in the circuit is so that I can turn ...
150 views

### Recommendations for essential measurement/bench tools for HV experimentation

I'm making plasma sculptures, and am also really interested in making big arcs and tesla coils. I started with some newer TV flybacks and the 2N3055 single-transistor flyback driver, and am moving on ...
123 views

### what is the default internal clock for pic16f1946?

While going through the data sheet, section 5.3.1 says: "Default system oscillator determined by FOSC bits in Configuration Word 1". How can find the value of this default clock, is it 8MHz or 31khz? ...
4k views

### Do PIC micorcontrollers NEED an external oscillator?

I'm trying to write my first and a simple program on a pic16LF84, but I'm confused as to whether an external oscillator is required or optional. I'm reading a pdf called "Book: PIC Microcontrollers ...
383 views

### No LSE connection to STM32. Is it OK?

I'm developing board which have STM32F103VET6. I don't need RTC so is it OK to not connect the OSE32_* pins to external oscillator? Will there be any side-effects? All the reference design I found all ...
544 views

### Low power, low voltage, slow (0.1Hz) oscillator?

I had the opportunity to analyze a very interesting circuit today using a programmable unijunction transistor as a timer. The power supply varies, and the circuit must operate on under 10uA of ...
743 views

### How to get a PIC12F1822 running at 32MHz

I just can't get my PIC12F1822 to switch to 32MHz (8MHz + 4xPLL) I am telling OSCCON to switch to 8MHz, but, according to the debugger, that value is never loaded into it! I also wait for the High ...
547 views

### Choicing crystal or external oscillator for time critical project on PIC18F

Need to learn how making frequency counter (or any time critical project) using PIC18F that display output over USB. Having choice of 3 clock sources: ±50ppm 4.0000 MHZ crystal ATP040SM 4.0000 MHZ ...
1k views

### Using microcontroller as oscillator for high voltage power suppy?

MightyOhm has designed a geiger counter which is here. I am not very clear but I think he is using the 555 timer as an oscillator in the high voltage power supply section. I've attached his schematic ...