Tagged Questions

2
votes
2answers
135 views

Expanding Range Of Analog Values From Temperature Sensor

I'm trying to build a temperature controlled relay module with an ATtiny45 ( Arduino UNO R3 as ISP ) and a NXP KTY81-222 Temperature Sensor. The temperature range i want to monitor is 20°C to 30°C. ...
2
votes
1answer
76 views

Reversing a .5-4.5V analog sensor output to 5V-0V

I have a pulse width modulation (PWM) control board that uses a 0-5V input via a potentiometer to control a DC motor speed. As I understand how this works, the potentiometer goes from 0% PWM at 0V to ...
4
votes
2answers
99 views

Connecting Analog Signals Between Boards

When you have a sensor with an analog output on one board, and an analog-to-digital converter (ADC) on another board, what's the best practice in connecting them together? For example, if you have a ...
4
votes
4answers
242 views

How to calculate permittivity of a fluid

I am confused about calculating permittivity of a fluid. Permittivity differs from one fluid to another. $$\epsilon=\epsilon_r\epsilon_0$$ Since it is an electrical property combined with an ...
4
votes
1answer
275 views

Limiting, scaling and biasing analog input (ADC) of microcontroller

I have current transformer coils to monitor a gas-powered AC generator output (A & B) and 4 load circuits. The output of the T1 coil with a 1500 watt load is about 30Vpp. Will this circuit ...
0
votes
2answers
433 views

SCT sensor to 0-10v analog input

I'm trying to read values from a SCT-013-030 sensor that gives 0-1vac readings . My board analog inputs are 0-10vdc,giving me a value from 0 to 65500 . I need to know what is the best method of ...
4
votes
1answer
166 views

Read analog envelope by 8051

I am having a serious issue here. I've bought a Maxbotix XL ultrasonic sensor but I didn't know that it is the AE version, that does not come with pulse width, it comes with Analog Envelope. I have a ...
2
votes
1answer
434 views

Amplifying signal from CO2 Sensor

I am trying to amplify a MG811 CO2 sensor to a range readable by an ATMEGA2560 (0-5v). I have other analog sensors, so do not want to change ref voltage on Atmega. I have found a module that scales ...
6
votes
3answers
292 views

How to design for a component that says “Electrical Design: DC PNP” in the datasheet?

I'm not a guy from electrical engineering and I'm having a little trouble with a small garage project that I'm working on. I want to use a photoelectric sensor to measure distances. I'll probably ...
3
votes
3answers
148 views

Digital or analog transmission for transmitting data off-board?

I have some digital sensors with ADC build in and the problem is this type of sensor have lots of control pin. It is hard to separate this sensors from my mcu board. Analog sensors are much simple ...
2
votes
1answer
116 views

ADC Preliminary Design

I am designing a circuit, to use an ADC(mcp3008) to read voltage, current, and temperature sensors. I have a few questons about this, as I have never done this before. I am going to use single ...
2
votes
5answers
306 views

Are the resistance values (R1 and R2) in this circuit reasonable?

This simplified circuit is intended to sense two limit switches (which can never be closed simultaneously-- at least in theory). The voltmeter shown is a place-holder for a connection to an analog ...
1
vote
2answers
819 views

How much current is consumed by an avr analog sensor?

I'm trying to measure a small analog device that emits about a volt (I believe up to 5V, but I've not measured at extremes yet) AC. I rectify the reading to DC, but I'm really interested in getting ...
7
votes
2answers
266 views

Triggering for geophone triangulation

I'm using three geophones to triangulate impact events inside the triangle, e.g. a mallet hitting the floor. Since the magnitude of the event is unknown, the position is calculated only by the timing ...
2
votes
2answers
493 views

Any issues with using an opamp as a constant current source for temperature sensing?

I understand that most people use a bridge circuit for RTD and possibly thermistor temperature sensing. I'm trying not to do that for several reasons. I'd like to use an opamp in the classic ...
4
votes
4answers
2k views

Reading RTD Temperature Sensor

I've had a number of issues getting good stable analog readings from an RTD temperature sensor. The temperature readings have a tendency to bounce as much as +/- 5 Deg C. The circuit is very basic, a ...
4
votes
2answers
2k views

What is the minimum supply voltage for an LM335?

The answer to this question is probably staring me in the face, but I just can't see it. I'm attempting to interface with an LM335AZ temperature sensor (datasheet) at 3.3V. The datasheet clearly ...