Voltage - Differential 20V

datalogging sensors


Data Harvest

Product Description

Monitor voltage over a fast short or long slow period of time in addition to spot measurements. 

53-sec capacitor - charge & discharge


Teaching applications:
  • Introductory electricity
  • Ohm’s law
  • Simple series and parallel circuits
  • Startup of a filament lamp
Extension and advanced ideas:
  • Induction of voltage in a coil
  • Electrical characteristics of components
  • Voltage and homemade sensors
  • Dynamo effect
  • Time constant, charge discharge of a capacitor

Download Voltage Sensor Manual  Doc No.: DS021 | Issue: 6



±20 V (Resolution 10 mV) 
Maximum Voltage ±27 V, Impedance 1 Meg ohm

Voltage sensors measure the potential difference between the ends of an electrical component and are connected in parallel. They can be used to measure both DC and low-voltage AC circuits. They should never be used with high voltages or household AC. The 4 mm plugs attach to most standard school’s electronics kits and power supplies.

A Voltage Sensor can be used in conjunction with a Current Sensor. Batteries are the first choice as the source of energy. An alternative is to use a fully isolated mains power supply with a regulated DC output (smoothed and fully rectified).

Be aware that some power supplies are ½ wave rectified producing an average rather than true DC, this sensor will ‘pick up’ the fluctuations in voltage and current from this type of power supply. 



Electricity from water power (Physics (11-14) eBook)
Use a simple water wheel to make electricity via generator. Monitor the voltage and or current over time against other variables e.g. flow, fall height etc.

Light and voltage (Physics (11-14) eBook)
Investigations with simple solar cells. Voltage produced, current, effect of light intensity, insolation angle etc.

Current and voltage in a series circuit (Physics (11-14) eBook)
This one of a series of investigations into current in a circuit. This part requires additional lamps and or cells to be added and the changes measured. 

Electrical Equivilence Of Heat (Physics (14-18) : Electricity & Heat eBook)
The experiment is very simple and compares the power generated in heating a resistance coil to the heat energy transferred to the water. Measurements are made in Joules to emphasise the transfer of energy. 

Stefan - Boltzmann law. (Physics (14-18) : Electricity & Heat eBook)
The experiment illustrates the Stefan - Boltzmann law. It does not give a value for the Boltzmann constant. A simple tungsten filament automotive lamp is used as the source of thermal radiation. The investigation tests if the radiation is really to the 4th power of temperature.

Calibration of a thermometer (Seebeck effect) (Physics (14-18) : Electricity & Heat eBook)
In the investigation two junctions are used, one is placed in a constantly cold temperature the other has varying temperatures applied to it. 

Specific heat capacity of a solid (Physics (14-18) : Electricity & Heat eBook)
This investigation will measure the specific heat capacity of a solid. A block of metal of known mass is heated by an electrical heater through a known number of degrees. The electrical energy required to create this temperature rise is determined and used to find the specific heat capacity. 

Specific heat capacity of a liquid (Physics (14-18) : Electricity & Heat eBook)
This investigation will measure the specific heat capacity of a liquid (water). A sample of water of known mass is heated by known number of degrees by an electrical heater.

What changes the current in a circuit? (Physics (14-18) : Electricity & Heat eBook)
Simple (revision) exercise to see how the number of cells in circuit changes the current.

What changes the current in a circuit (Physics (14-18) : Electricity & Heat eBook)
Alternative exercise using snapshot to collect data instead of reading values off a meters screen.

Good and bad conductors (Physics (14-18) : Electricity & Heat eBook)
This activity is a standard practical comparing current flow with different materials in a circuit. Strips of different conductors and insulators are provided for the pupils. Conductors are anything that let a current flow. 

Connecting resistors (Physics (14-18) : Electricity & Heat eBook)
Shows the current in circuit with different resistor values and combinations. Leads to resistor calculations. 

Current and voltage (Physics (14-18) : Electricity & Heat eBook)
Introductory activity to explore the relationship between current and voltage with an ohmic conductor. In this variant changes in voltage and current are measured against time. 

Current and voltage (Physics (14-18) : Electricity & Heat eBook)
Introductory activity to explore the relationship between current and voltage with an ohmic conductor. In this variant changes in voltage and current are plotted directly against each other, leading into characteristics of conductors / components. 

Simple series circuits (lamp resistors) (Physics (14-18) : Electricity & Heat eBook)
The effect of a component offering electrical resistance in circuit is revised.

Ohms Law (Physics (14-18) : Electricity & Heat eBook)
A study of Ohm's law for resistors. Collects data graphically against time to allow the students to change plot to voltage vs current. 

Ohms law current vs voltage plot (34a) (Physics (14-18) : Electricity & Heat eBook)
Activity set up to let the software plot voltage vs current directly. Opens the possibility of more investigation of the relationship between voltage and current and the type of resistance. Resistance can also be calculated and plotted. 

Electrical characteristics (LED, resistor and filament lamp) (Physics (14-18) : Electricity & Heat eBook)
Create voltage current curves for LED, resistor and filament lamp. This worksheet assumes all three curves in one teaching session. 35a and 35b restrict to fewer devices per session. 

Electrical characteristics (resistor and filament lamp) (Physics (14-18) : Electricity & Heat eBook)
Specific worksheet to produce voltage current curves for a resistor and filament lamp (ohmic and non ohmic resistance)

Capacitors: charge stored. (Physics (14-18) : Electricity & Heat eBook)
Collect voltage and current data during a capacitor charge and discharge cycle. Use built in tools to find the energy transferred and stored. 

Efficiency of an electric motor / generator (Physics (14-18) : Electricity & Heat eBook)
The efficiency of a motor / generator is determined. This worksheets has details of the motor and generator calculations and method 

Efficiency of an electric generator (Physics (14-18) : Electricity & Heat eBook)
Determines the efficiency of a generator. Uses a falling mass as the energy source and records voltage and current to produce power curves. 

Efficiency of an electric motor (Physics (14-18) : Electricity & Heat eBook)
uses a known mass lifted through a known distance compared to the power required by a motor to lift the mass. 

Efficiency of a transformer (Physics (14-18) : Electricity & Heat eBook)
Simple experiment to measure volts in and volts out. Data collected can be used to show phase match / difference and power in and power out.

Diodes: ac rectification (Physics (14-18) : Electricity & Heat eBook)
In this investigation, you will find out how diodes are used as rectifiers, and learn about the basic circuits in use in rectifier circuits. 

Diodes ac bridge rectification (Physics (14-18) : Electricity & Heat eBook)
discover and investigate how diodes are used as rectifiers, and learn about the basic circuits in use in rectifier circuits. Conversion of an ac current to dc.

Input characteristic of a transistor (Physics (14-18) : Electricity & Heat eBook)
This investigation is going to study the input characteristics of the transistor across the B–E terminals by applying an alternating voltage, and measuring the voltage across and the current flowing through the B-E junction. 

Transistor as a switch and current amplifier (Physics (14-18) : Electricity & Heat eBook)
This investigation will show the students that, 1. The base voltage controls the collector emitter current. 2. A small change in the base voltage causes a large change in the collector voltage. 3. The use of this change in the collector voltage to provide switching. Amplification of current is also considered. 

Reactance and phase in a capacitor (Physics (14-18) : Electricity & Heat eBook)
You are going to measure the current through and voltage across the capacitor at different frequencies. From the data, you will calculate the reactance Xc of the capacitor at different frequencies. 

Impedance and phase difference with frequency (Physics (14-18) : Electricity & Heat eBook)
Investigate how, in a series C-R circuit, resistance and capacitance combine to affect the flow of an ac current.

L-R circuits: How does Impendance change with frequency? (Physics (14-18) : Electricity & Heat eBook)
The investigation will show: 1. How impedance of a series l-R circuit increases with frequency. 2. The formula for calculating impedance of a series L-R circuit 

Resonance In an LCR circuit (Physics (14-18) : Electricity & Heat eBook)
To find the frequency at which the impedance becomes purely resistive - the resonant frequency. 


Why do bulbs blow (Science At Work (11-16) eBook)
This activity uses this familiar event to introduce the idea of power surges and to calculate resistance changes. It is a practical introduction to the relationship between voltage and current and the problem of correctly fusing devices in a home for safety.

Mp3 (Science At Work (11-16) eBook)
In this activity the role of the number of samples in collected data is considered using the problem of sound quality in MP3 players as the stimulus. The change in the information in the data files created is easily seen.

Electric from sunlight (Science At Work (11-16) eBook)
In this investigation you will take a small solar panel and investigate how much light is needed to make electricity. The quantity of electricity produced will be measured as its voltage. 

Why is electric ac (Science At Work (11-16) eBook)
This experiment tries to show why it is that the electricity supply is created as an alternating current (AC). 

HK$ 557.00