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125 Khz

41 Threads found on edaboard.com: 125 Khz

Hello. I wanna read 125 khz proximity card. I added EM4095 in my circuit. But I have noticed that EM4095 supply voltage is 5V. I wanna use same chip but runs logic level 3.3V and cheap. Can you suggest 3.3V 125 khz transmitter. Thanks

capacitor selection for antenna tuning

What frequency? The term "proximity card" refers to the older 125 khz devices as distinct to the newer 13.56 MHz contactless smartcards. You can also use diodes used as a varicap for fine tuning which increase in pF size with power rating but wide tolerance for any diode.

ofdm bit rate with various subcarriers and symbol rate

I like do some math. a. 20*1*48*125K*4=480M. b. 20*1*24*125*4+20*1*125*6=600M

Can't make oscillator with CMOS inverter

Hi all guys, I am trying to make an oscillator using CMOS inverter for quite some time and it won't oscillate at desired frequency. I want to make 125 khz oscillator using following schematic (the element values are not relevant for desired frequency): 111933 The circuit simply won't oscila

can any body explain to me how can this circuit produce an alternating current

I presume "PWM" means in this case that a PIC timer is used in PWM mode to generate a square wave of fixed duty cycle. We get a 5V square wave at the MOSFET drain (or less, depending on the LC values). It will generate an AC current through the LC circuit. If LC is tuned to 125 khz, it's mostly a 125 khz sine current.

RFID &PIC 18f452

Can someone help me with MikroC program for interfacing RFID reader(serial,125 khz) with pic18f452

The HF (13.56 MHz) reader can only communicate with HF tags. However, there are HF tags which can work at 125 khz or 900 MHz at the same time.

Direct Digital Frequency Synthesis with fractional steps

Hi, I implemented a integer-N pll based frequency synthesizer but it takes 2m second to lock at desired frequency. But my adviser didn't accept it. Now I want to use DDFS but my project's details are as below: 1- output frequency between 880 MHz and 912 MHz 2- reference frequency 880 MHz or 900 MHz 3- step size 125 khz And the question i

EAS+RFID Tag Configuration

Diffferent RFID standards use different frequencies, e.g. 125 khz, 13.56 MHz and 900 MHz. RF EAS tags are simple passive LC resonators, see Wikipedia article: These tags are essentially an LC tank circuit that has a resonance peak anywhere from 1.75 MHz to 9.5 MHz. The most p

Does anyone know on how to initialize ADC on ATMEGA128 ?

I tried to init like this : void adc_init() { // enable ADC, select ADC clock = F_CPU / 128 (i.e. 125 khz) ADCSRA = (1<

COSTAS loop implementation using System Generator tool (ISE)

I have developed a simple costas loop for BPSK demodulation. It is working fine for 8Mbps data rate BPSK. The overall sampling freq is 125 MHZ. Inside the loop, the corresponding FIR and loop filters are running at 25 MHz. The lock range achieving is +100 khz to -100 khz of centre 30 Mhz. Now, I am updated the same for QPSK demodulation. (...)

Initializing signal with 125Khz.

Hi, I have small problem with generating sine wave initially with 125 khz. This seems very simple but it took lot of time from me but i couldn't figure it out what is the problem. I am using CodeVisionAVR compiler. I am using ATmega32-A micro controller, AD9833 programmable wave form generator to generate sine wave. I have written the fallowi

RFID problem with pic16f

I have a problem with my project, its a rfid reader (125 khz) connected to pic16f877a with a LCD (works fine without rfid ).. after I connect them ,, I only see the cursor down , but nothing happens when I try to make it read the tags! First of all, are you sure the RFID reader is the version with TTL Se

RFID frequency identification

If the antenna has many thin wire turns it may be a system working around 125..145 khz. Many turns are requried to get the antenna coil in resonance with a capacitor. The transmitting antenna (reader antenna) also has many turns. If the antenna has about 10..20 turns and the transmitting (reader) antenna has one to some turns, it is very likely

ML‐91 NVIS antenna and design the roof rack antenna

I have to design a NVIS roof rack antenna for the following specifications. Frequency range: 3.3 ‐12.5 GHz. Power rating: 125 PEP Receive bandwidth: 45 khz at 3 GHz and 290 khz at 12.5 GHz. Tuning method: Continuously variable tuning capacitor. Drive Method: Microprocessor controlled precision stepper motor. Dimensions: (...)

I specifically need a total analog circuit... As far as your RFID is transmitting data according to an existing 125 khz standard, it will go digital. Thus a RFID system can't be totally analog.

Qualitiy factor of an inductor

Dear friends, I designed loop antenna for my RFID and wanted to fin out its inductance, quality factor and DCresistance. I used LCR meter and found out that L=742\mu H and Q=19.63. all measurements were made at 100khz and that is fixed for the device. Can anyone tell me how to find the Quality factor at 125khz since t

How to read and write to an unknown RFID chip

First you have to identify the RFID standrad implemented by the chip. ISO/IEC 14443 (13.56 MHz) would be a promising candidate, but is may be also a low frequency (e.g. 125 khz) standard, or some less common protocol. A 13.56 MHz standard would be most simply identified by trying to read out the chip with a multiprotocol RFID reader.You may want to

How to start IRFP250 with PWM?

Hello How to start transistor IRFP250 by the microcontroller PWM? Microcontroller PWM output frequency is 125 khz. This transistor must turn on 10 Power LED 1 Watt. This is a RGB projector. best regards