# What voltage does a Resistor temperature detector put out?

###### Wiki User

###### May 26, 2009 6:09AM

None. An RTD is a passive device. It changes resistance as the temp varies. Your circuit must basically measure the resistance to determine temp. There are many different types of RTD's, each with it's own temperature curve.

## Related Questions

An electric heater is a resistor. It is a resistor with the right amount of resistance to take the required amount of power at the specified voltage. With a case to put it in and louvres to let the warm air circulate, that is a heater. Resistance in ohms is equal to the voltage-squared and divided by the watts.

12 volts...! The voltage drop across a 2 ohm resistor depends on the current flowing through it. As voltage (E) equals current (I) times resistance (R), if 1/2 amp is flowing through your 2 ohm resistor, 1/2 times 2 = 1 volt. If 1 amp is flowing through your 2 ohm resistor, 1 times 2 = 2 amps. Piece of cake. If the two ohm resistor is the only component in the circuit, it will drop whatever the applied voltage is. Put a 2 ohm resistor across a 6 volt battery, it drops 6 volts. If you put your 2 ohm resistor across a 9 volt battery, it drops 9 volts. Another way to say voltage drop may help. The voltage drop across a resistor is the voltage it "feels" when in a circuit. And that last couple of examples says that very well. In a circuit where a given resistor is the only component, it drops all the voltage in the circuit. It "feels" all the voltage in the circuit. In a circuit where there are 2 resistors of equal value in series, each one drops or "feels" half of the applied voltage. (The sum of the voltage drops equals the applied voltage.) As you work more with simple circuits using resistors in different arrangements with a given voltage source, try thinking of the voltage drop of a resistor as the voltage it "feels" when the circuit is energized.

The heat generated by any particular resistor depends (at least electrically) solely on the power it dissipates. Power dissipation in a resistor is equal to current squared times resistance, and the current through the resistor is equal to the voltage across it divided by the resistance. If we take a 10 ohm resistor ('your resistor') and put it in a series circuit such that there is 10 volts across your resistor, the current through it will be 1 ampere (10/10=1). the power dissipated will be 10 watts (1^2 * 10=10). If we put your resistor in a parallel circuit that also puts 10 volts across it, then the current and power will be the same. Your resistor does not know or care where the voltage came from. From this point of view, once you get down to the voltage across the resistor, it does not matter what type of circuit it is in. On the other hand, for any given power supply voltage, then the type of circuit and the value of external components certainly does affect the terminal voltage and thus the current through as well as the power dissipated by the resistor. In a parallel circuit, the voltage across your resistor remains basically the same no matter what resistance you put in parallel with it (unless you overload the power supply or the power supply has high internal resistance). In this case, the voltage across the resistor is the same as the power supply, current is I=E/R, R being that resistor only, and power is P=I^2 * R. In a series circuit the current through the resistors is I=E/R, R being the total resistance (including the other resistor(s)). The power dissipation in your resistor will then be P=I^2 * R, I being the series current we just calculated, and R being your resistor only. Since the other resistors affect the current, and since the current is the same no matter where you measure in a series circuit, then the voltage across your resistor and thus the power dissipation will be affected. The voltage across your resistor will be E=I*R, I being the series current we just calculated, and R being your resistor only. So, while the calculation for power dissipated in a particular resistor does not change relative to what type of circuit it is in, the calculation to arrive at the voltage across the resistor and/or the current through it (which you will then need to calculate power) does. Keep in mind there are other mechanical parameters that influence the actual case temperature of the resistor. Physical size of the case, composition, and airflow velocity, if any, will alter the case-to-ambient thermal conductivity. Ambient temperature will also be a factor in the final temperature.

Depends on the current. Put a resistor in-line with the current, then measure the voltage across the resistor. V=RI. So, divide the measured voltage by resistor value. Be careful with the size of the resistor, as Power dissipated in a resistor is R*I^2 or V^2/2. So, a 1-Amp current into a 1 Ohm resistor will result in a 1Watt power dissipated in the resistor. If it's too small, it'll burn. Also, notice that if you do that, you haven't measured the current in the original circuit. You've measured the current when an extra resistor is installed in the original circuit, and that's different.

Simply put, the purpose of a resistor is to 'resist' the flow of current. Ohm's Law tells us that for a given voltage, the larger the resistance, or value of that resistor, the lower the current that will flow. Ohm's Law states that I (current) = E (voltage) / R (resistance) - where current is measured in amps, voltage is measured in volts and resistance is measured in ohms.

Without actually performing a failure analysis on the specific resistor, there is no way to know what caused the blower motor resistor to fail. However, there are two likely causes, design and/or implementation. First a little info on the setup. The blower motor is a brushed motor. One way to use the same motor and get different speeds is to vary the voltage to the motor. More voltage will give more speed, less voltage will give less speed. One way to "adjust" the voltage to the motor is to put a resistor in the power line to the motor. The resistor will "absorb" voltage and give off the absorbed voltage as heat. The Malibu uses 4 different resistors to create 5 total blower speeds. The 5th setting is with no resistor in line. As the resistor absorbs voltage and gives off heat, eventually the resistor will burn out and need to be replaced. There are many different quality levels of resistors. Some resistors are high quality and will last longer than the car will be used. Some resistors are low quality and will fail while the car is still in service. Engineering selected the particular resistor used in the resistor pack. Perhaps, if the resistor burned out, the design is at fault as the part wasn't selected correctly. Implementation could be how the part was installed, perhaps the solder joint (how the resistor is connected) failed as the solder wasn't flowed correctly. There is nothing you could have done as a consumer to increase or decrease the life of the resistor.

Resistor values are given in ohms. A value may be selected to deliver a specific current at a given voltage. This is given in what is known as Ohm's Law where: Voltage (V) = Current (A) X Resistance (Ohm) A 12ohm resistor placed across a 12V battery would pass 1Amp of current and put out 12W of heat.

Many multimeters have an ampere scale. The basic idea is that the current has to go through the meter in series with a load. ( meters have a fuse for the forgetful). If there is no ampere scale, put a small value precision resistor (like a 0.01 ohm 5-20W)in series with the load and measure the voltage drop across the resistor. Let's say the voltage across the resistor is 1 Volt, then 1V/0.01=100 Amps.

A resistor is an Electrical component that is uses to divide current and voltage up. They are used to make sure a certain component (for example an LED) gets the correct amount of current and voltage to preform efficently. Resistors have more uses than the ones I have just described, one more example is they can make the timing of a timer change. If u put a bigger resistor then the time delay goes up ect.

A: A thermocouple is created from wires of two different metal welded together to form two junctions. These two junctions will generate a dc voltage according to the temperature difference between the junctions. A thermistor is a resistor that will change resistance as temperature is impressed on it. A thermistor measures temperature. A thermocouple measures temperature difference between two points. To measure temperature using a thermocouple, you need to know the temperature of one of the points. The two junctions are sometimes called the "hot junction" and "cold junction." It used to be standard to put the cold junction into a known temperature environment--often an ice water bath, since that is known to be 0 degC. The hot junction is then located at the point where temperature is to be sensed. Thermocouple voltage vs. temperature difference is non-linear and the voltage difference varies depending on the materials used to create the thermocouple. For example, for a chromel-alumel TC (called Type-K), the curve is a 9th order polynomial. To convert voltage to temperature, either the polynomial must be calculated for each measurement or entries in a table used.

you would have to put some type of resistor in the circuit with the motor...the resistor would have to be in series with the motor and would have to be of a high enough value to lower the voltage by 9 volts....There is a formula for working this out but you would need the amperage of the motor to figure this....