New answers tagged ttl
1
From page 3-13 of the data sheet you can glean that the front panel inputs have a programmable termination of 50 Ω to ground, which can be used or not. They also have programmable voltage threshold, so if you want to drive at less than 5 V, you may.
For the lowest drive strength requirement from you box, use a series 50 Ω output impedance, to an unterminated ...
0
A balloon that the device under test can be secured to or held against.
The balloon can be pulsed at a frequency of choice using perhaps a linear actuator or motor to hit the balloon with a “hammer” or something similar.
1
It looks like the video is showing a configuration where the emitter of an NPN transistor is grounded, and the transistor turn on when a positive base voltage is applied.
The TTL book you mentioned is probably talking about an open emitter configuration, with the emitter being the input and the base connected to a positive supply voltage, through a resistor. ...
4
I realize this circuit requires a VR pickup sensor, and so the
LM2907/LM2917 must rely on triggering off of zero-crossings.
The data sheet tells you that a zero cross does not trigger anything: -
You need to exceed a positive threshold and then return back below a negative threshold or it won't register anything - this is to avoid noise triggering causing ...
3
Use this kind of RC circuit. The op amp in this circuit is the internal op amp of your tachometer IC. The RC network will change your 0-5V signal to a -2.5V to 2.5V signal. R1 should be around 10k, C1 should be selected such that the RC time constant is much (at least 5 times) greater than the time period of the square wave which you are expecting.
2
The data sheet for the TACH chip that you linked makes it very clear how the inputs operate. See this:
9.3 Feature Description
9.3.1 Differential Input
This device features a Schmitt-Trigger comparator that is the first stage in converting the input signal. Every time the output of the comparator flips between high and low correlates to a half cycle elapsing ...
2
This Tachometer IC uses any repetitive to make edge-triggered fixed pulse width using a Schmitt comparator and a one-shot.
If you have a unipolar logic level pulse, then the comparator needs a reference Vdc with a resistor divider to the Vin midpoint voltage or 2.5V in your case using 2 equal large R values with a small filter cap.
Alternatively Vin- = gnd , ...
answered Jun 17 at 16:55
Tony Stewart Sunnyskyguy EE75
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0
I'm looking for guidelines like "don't connect a pin of type A to a pin of type B without a gate of type G in between", or "be sure to add resistors/caps here and here", or "power up this pin/chip before this other pin/chip" or "use a such-and-such circuit to condition the power" ...
These "tips" are instructions given in the data sheet and developer's ...
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