This sensor measures soil moisture levels by capacitive sensing, rather than resistive sensing like other common types of moisture sensor. It is made from a corrosion-resistant material giving it a long service life. Simply insert it into the soil and impress your friends with the real-time soil moisture data!
The sensor includes an on-board voltage regulator which gives it an operating voltage range of 3.3 to 5.5V. It is compatible with low-voltage MCUs (both 3.3V and 5V logic). To make it compatible with a Raspberry Pi, an ADC converter is required. The sensor is compatible with the DFRobot 3-pin 'Gravity' interface, so it can be directly connected to the Gravity I/O Expansion Shield.
This Arduino compatible sound level meter (also known as a decibel meter or noise meter) uses sensitive circuitry and a low-noise microphone to enable it to accurately measure the sound level of the surrounding environment. It can be used for environmental noise testing, such as a highway noise monitoring station, bedroom noise monitoring, etc. Nowadays, there are many kinds of sounds surrounding us, some of which are very loud. It is essential to measure whether the sound is noisy enough to do damage to our health.
This sound level meter is compatible with Arduino and is plug-and-play with no soldering required. It supports 3.3 to 5.0V input voltage, 0.6 to 2.6V voltage output. The decibel value is linear with the output voltage, which gives a simple conversion, without complex algorithms.
Features:
High Precision: use instrument circuit, low noise microphone
Wide voltage input: 3.3 to 5.0V
Simple conversion: linear analogue output, 0.6 to 2.6V linear correspondence 30 to 130dBA, no complex algorithm is required
A simple educational construction set for beginners from 8 years upward. No soldering is needed, cables are simply screwed on, or twisted together. Experiments are described with helpful instructions.
Small lamp circuit
Electromagnetism
Current detection using a compass needle
Radio transmitter system
Generator
Make a battery
Conductivity of water
LED test I
LED test II
Kit includes: compass with coil for current indicator, small lamp, LED with integrated resistor, electric motor, terminals, zinc nail, copper board 10 x 50mm, connecting wire and detailed instructions
A kit of parts to build a 'Wheel of fortune' style, random selector, ideal for electronic games, quizzes, etc.
After releasing the pushbutton, all of the LEDs light except for one, creating a gap that 'runs' quickly round the circle of 10 LEDs. The pattern then slows and stops randomly with one LED lit. Having all of the LEDs lit during operation greatly enhances the decorative effect of the kit.
This high quality piezo-tweeter can be connected directly to an amplifier or diplexer. The tweeter has a vaulted aluminium spherical cap and no conical membrane as is usual with flare loudspeakers. Due to the aluminium cap the acoustic pressure is not so strong as with comparable piezo-tweeters, but in return, the loudspeaker has a very broad angle of radiation and a brilliant sound up to 45,000Hz. This tweeter is therefore especially suitable as an ultrasonic loudspeaker for the control of pests, rodents, vermin, etc.
This adjustable DC to DC converter module is ideal for operating devices that use a lower voltage than that available from a battery or fixed voltage power supply unit. The output of the converter is short-circuit-proof and regulated.
Input voltage: 6 to 28V DC
Output voltage: 3 to 15V DC
Max. output current 1.5A
Kemo type M015N
Note: The input voltage must be at least 3V DC higher than the required output voltage.
A sturdy 12W amplifier module for general-purpose use as a speaker power amplifier. The module is cast, moisture-proof and vibration-proof. The casting mass and module housing are made of a special highly heat-conductive plastic which means that no additional heat sink is necessary.
Convenient modular construction
Extra cooling not required.
Electronically protected against overheating and overload
Please see the Technical Specification table for full details
The Kemo M032S is a 12W universal audio amplifier that can be used in any application where an audio signal needs to be amplified, such as music systems, car radios, CCTV systems, etc. The M032S has a mono phono input jack, an integrated volume control, speaker cables for the output and a 2.5mm miniature jack socket for the power supply input. The amplifier operates on any voltage from 6 to 16V DC.
At only 71 x 50 x 42mm, the amplifier module is compact enough to be integrated into tight spaces and into other appliances. Two lugs with screw holes, located at either side of the module provide a simple mounting method.
A sturdy 18W amplifier module for general-purpose use as a speaker power amplifier. The module is cast, moisture-proof and vibration-proof. The casting mass and module housing are made of a special highly heat-conductive plastic which means that no additional heat sink is necessary.
Convenient modular construction
Extra cooling not required.
Electronically protected against overheating and overload
Please see the Technical Specification table for full details
A sturdy 40W amplifier module for general-purpose use as a speaker power amplifier. The module is cast, moisture-proof and vibration-proof. The casting mass and module housing are made of a special highly heat-conductive plastic which means that no additional heat sink is necessary.
Convenient modular construction
Extra cooling not required.
Electronically protected against overheating and overload
Please see the Technical Specification table for full details
This voltage convertor module is ideal for operating 12V DC vehicle accessories and equipment, from a 24V battery source. E.g. using a conventional 12V car radio in a truck or boat with a 24V supply. The output of the module is short-circuit proof and voltage regulated.
Input voltage range: 24 to 28V DC
Output voltage: 13.8V DC
Output current: 3A max.
Kemo type M038N
Please note that this unit becomes hot in normal use and must be mounted on a metal surface to allow heat to be conducted away. The use of heat transfer paste between the unit and the metal surface is recommended.
This Kemo preamplifier module is suitable for microphones and other general-purpose audio uses. The compact-sized module is simply connected between a weak signal source and the power amplifier.
Amplifies weak signal sources for feeding into a power amplifier
This powerful ultrasonic generator is ideal for deterring rats, mice, wild rabbits, birds, etc. When connected to a suitable piezo speaker, the module produces an ultrasonic tone with a constantly changing frequency. Humans can usually only hear frequencies up to 20kHz, so only the animals will hear the sound. An LED on the module indicates when it is in operation. The module can power up to 5 piezoelectric speakers. Approximate size 60 x 45 x 23mm
Max. Range (open field): 25m
Kemo type M048
Note: Piezo speaker output connections are not polarised. Will function either way round.
Note: Piezo speakers not included.
Note: Requires a suitable 12-15VDC Supply >500mA (Not included).
Note: Suitable for indoor use as is, a separate suitable enclosure will be required for outdoor use.
This module monitors the charge status of a 12V lead-acid car battery and recharges it automatically when the voltage falls. When the battery is full, the module shuts off the charging process and continues to monitor the battery. The module is ideal for lead-acid batteries in alarm systems, holiday cottages, caravans, campers, etc., to keep them constantly topped-up without overcharging.
Automatic charge stop at approx. 13.8 to 14.2V
Short-circuit and reverse current protected
Also suitable as charge regulator for solar panels
Switches on other devices with the built-in relay contact after pushing the button and automatically switches them off again after a set time. The time can be stopped any point by pressing the second button. Two push buttons are required for use.Connection via flat plug on the module · 2 LED display (1 x LED operating voltage, 1 x LED relay "ON" ).
This electronic light-operated switch automatically turns on lights or other appliances when darkness falls and switches them off again at daybreak. The module can also work in reverse, i.e., on at daybreak and off when darkness falls. Potential-free loads up to 3A can be switched.
Ideal for night-lights, security lighting, advertising displays, fountains, etc.
Light sensitivity can be varied by partially covering the sensor
This module consists of an LED soldered to a constant current circuit. It can be connected to any voltage between 4 and 30V DC. The LED shines with almost constant brightness regardless of voltage and has a current consumption of approx. 15mA. No additional protective resistor is required. If required, the supplied LED can be substituted for any other similar LED. It is also possible to connect several LEDs in series.
Avoid the nuisance and damaging effects of a discharged car battery with the Kemo M148A battery guard module. The module cuts power to accessories if the battery voltage drops below the set minimum. (Choose between 10.4V, 11V, 12V, 13V, 13.3V). When regular voltage is restored, i.e. when battery is recharged, the power to accessoriess is re-established.
Avoid flat batteries due to devices left switched on
Module cuts power to devices when battery reaches low charge
This solar charging controller module can be connected between a 12V DC solar cell (open circuit voltage 14 to 30V DC) and a 12V DC battery to prevent overcharging of the battery.
LEDs indicate 'battery full' (approx. 14.4 V DC) and 'charging
Kemo's M152 rain sensor module combines a liquid-sensing plate and a 12V normally-open relay contact to produce a switching operation controlled by the detection of rain or snow. The relay is activated when rain is detected on the sensor plate and de-activated when water is no longer present. Integrated heating avoids water staying on the plate once it has stopped raining. Potential projects include motorised windows, automated awnings or even automatic washing line covers!
To use this module with 240V appliances, an additional mains voltage rated relay is required, activated by the module's low voltage relay. Choice of this relay depends on your application.
Note: Water is only conductive when contaminated with dirt. For best results, it is desirable that the rain water first flows over a roof or via the gutter, to ensure reliable operation of the sensor.
Small size - integrates easily into your project
Automate your appliances to switch on when it rains or snows
Relay is activated when liquid contacts sensor plate
Heated sensor area avoids activation by standing water
Integrated 12V, 2A SPST-NO relay
Sensor heating is automatic when it comes in contact with rain
This module has a very sensitive input for a pair of probes. When the 2 probes come into contact with water, a relay switches on, which can be used to control sirens, lights, pumps, etc.
The water sensors use an extremely low voltage in order to prevent the otherwise usual oxidisation through galvanic currents.
The Kemo M168 Car Voltage Spike Protector permanently suppresses all voltage spikes in the on-board power, protecting sensitive on-board electrics against damage during jump starting or battery charging. The voltage spike protector can also help to extend the life of car bulbs. Simply connect the module parallel with the 12V DC car battery.
Prolongs lifetime of incandescent bulbs by absorbing voltage spikes
The Kemo P5123 Miniature Piezo Tweeter Speaker has an aluminium spherical cap for especially low distortion and constant high pitch radiation. It is highly suitable for ultrasonic vermin scarers due to its robust construction and small size.
This low-cost project uses an 8-pin microcontroller to create a random output electronic dice display with LED spots. The kit includes extensive project notes that go from an introduction to the components all the way to programming the microcontroller.
This stereo audio amplifier kit gives you more power and more volume than our standard kits. Each channel can deliver up to 10W for a louder, crisper sound. The kit is supplied without speakers so you are free to choose your own. Supplied with assembly instructions.
Kit includes PCB and all components to make one stereo amplifier
Supplied without speakers
10W power per channel
Stereo connecting cable supplied 3.5mm male to male
Requires 4 x AA batteries (not included)
Amplifier dimensions are 50mm width x 75mm length x 30mm height
Note: Colour of individual components may vary from those shown.
This stereo audio amplifier kit gives you more power and more volume than our standard kits. Each channel can deliver up to 10W for a louder, crisper sound. The kit is supplied complete with speakers. Supplied with assembly instructions.
Kit includes PCB and all components to make one stereo amplifier
Supplied complete with speakers (35-1400) which are 80mm in diameter by 50mm high with 8 ohm impedance
10W power per channel
Stereo connecting cable supplied 3.5mm male to male
Requires 4 x AA batteries (not included)
Amplifier dimensions are 50mm width x 75mm length x 30mm height
Note: Colour of individual components may vary from those shown
Fully-functional uncased memory sticks, ideal for allowing students to design and make their own case.
The finished product is a practical item that students can keep for transporting homework and other data. The rear section of the PCB from the front of the rectangular hole does not have any components on it so can be used for fixing part of the case. Case designs should not protrude any further than the front of the circuit board so that the USB connector is not obscured. The maximum thickness of the PCB and components is 5mm.
The memory stick is an ideal basis for a 3D Printing Project to design and make a suitable case. The cases are relatively small, use only a small amount of filament and are reasonably quick to print. Some 3D printers allow several cases to be printed at once.
This stereo audio amplifier kit gives you more power and more volume than our standard kits. Each channel can deliver up to 2.5W for a louder, crisper sound. The kit is supplied complete with speakers.
Kit includes PCB and all components to make one stereo amplifier
2.5W power per channel
Connecting cable supplied
Supplied complete with speakers
Requires 4x AA batteries (not included)
Please note: Component locations C16, C17, U2 and J4 on PCB are intended for future development and are not supplied.
This stereo audio amplifier kit gives you more power and more volume than our standard kits. Each channel can deliver up to 2.5W for a louder, crisper sound. The kit is supplied without speakers so you are free to choose your own.
Kit includes PCB and all components to make one stereo amplifier
A pack of components to build 10 humidity sensors, ideal for class projects with students working in small groups.
This general-purpose circuit detects changes in humidity and switches the LED on or off accordingly. The sensitivity of the circuit can be set by adjusting a potentiometer.
A pack of 5 high quality printed circuit boards for the Rapid LDR PCB project kit, 70-0245. PCBs are included with the kits, but are available separately for those who wish to source their own components.
A pack of 5 high quality printed circuit boards for the Rapid thermistor project kit, 70-0315. PCBs are included with the kits, but are available separately for those who wish to source their own components.
A pack of components to build 10 temperature sensors, ideal for class projects with students working in small groups.
This general-purpose temperature-sensing circuit uses a thermistor to detect changes in temperature and switches the LED on or off accordingly. The sensitivity of the circuit can be set by adjusting a potentiometer.
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