LM2917 DATASHEET PDF
The LM LM series are monolithic frequency to voltage converters with a high gain op amp comparator de- signed to operate a relay lamp or other load. uses a charge pump technique and offers frequency doubling for low ripple, full input protection in two versions (LM,. LM) and its. The LM, LM series are monolithic frequency to voltage converters with a high gain op Details, datasheet, quote on part number: LM
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I think the problem is my Internal Zener references.
Pin 11 and Pin 1 are the two inputs of a voltage comparator. You want it to keep the measurements stable. I’m not game to hook it to my ‘duino nor can I be buggered going out to the bike yet All the capacitors and resistors are connected to ground; I’m very llm2917 at this step. The charge pump is charging a capacitor which one?
I’m guessing the AC input is required to be centered on 0V, incidentally, but a DC blocking cap outside the chip would easily achieve that. Andy aka k 10 I need a circuit which generates 1mV voltage per 1Hz frequency. Now slightly more awake – Im thinking the grounding of the negative SigIN is ‘producing’ a voltage because it causes the various caps to discharge – not because it actually runs through the IC Then you stand a chance of getting the input to switch.
I want to learn working principle and internal circuit of the IC, and function of externally connected components especially C Checkout my projects development blog SLiDA.
You have fixed Pin 11 at about 0. To help save hands, I hooked an LED up to the output signal. Read towards lm29177 bottom of page 8 on the data sheet.
I’ve built this on a breadboard using a modified version of http: Since the chip was originally built to post-process a magnetic pickup for tachometer applications, the vatasheet crossing would be easy to arrange for by directly wiring the pickup coil across pins 1 and 8. I’m stuck with a pin LM – i’ve got an 8-pin on order now, but damn it, I want to get this to work. I have then used the datasheet as well as this schematic to convert to 14 pin How are you pulsing the 14V? What datazheet the function of the second opamp?
The sig-in line goes from 5.
Ideally, you’re going to need 8 pulses per second minimum, would be better for test purposes. Here’s a hand-waving explanation from a digital and software guy who has bumped in to sharp edges in the analog side The load is needed to convert the stored charge into a voltage that can be sensed, and pragmatically to provide a place for the stored charge to leak off into as frequency falls.
LM Datasheet(PDF) – National Semiconductor (TI)
I then have another supply, also grounded to the common ground, thats 14V. Sign up lm2971 log in Sign up using Google. Its datasheet is very old and it doesn’t explain function of the IC well. Then put a 10K resistor to the cathode of D3 and the other end of it to ground.