Hobbykit Ltd

Italian Police Siren - HK1019

The device is an electronic “Italian Police” type siren implemented entirely with discrete components. Two transistors form a clock generator with adjustable frequency, while another two transistors ..

1.94 €

Two-tone Siren - HK1020

The device is a two-tone electronic siren implemented using a single NE556 integrated circuit, which contains two 555 timers. The timers operate as multivibrators. The first timer generates a clock si..

2.94 €

Five-Channel Tone Control (Equalizer) - HK1026

The device is a five-channel passive tone control (equalizer) designed for adjusting the frequency response of an audio signal. The circuit is implemented using two transistors and passive RC filters...

2.15 €

Stereo Preamplifier with Single-Supply Power - HK1027

The device is a stereo preamplifier implemented using a TL082 operational amplifier (also marked as B082), operating with a single-supply power source. It is designed to amplify low-level audio signal..

1.94 €

Stereo Mixer - HK1028

The circuit represents a stereo audio mixer designed to mix up to four input signals. Inputs are provided for a tape deck, tuner, turntable and microphone, with each input adjustable according to the ..

5.05 €

Car Battery Monitor - HK1030

This device is designed for early detection of faults in the alternator - battery - starter circuit in vehicles with a 12 V electrical system. It monitors the system voltage and indicates the operatin..

1.33 €

Unipolar to Bipolar Power Supply Converter - HK1032

This device is a voltage converter that converts a unipolar DC supply into a bipolar power supply. When a unipolar input voltage is applied, a symmetrical bipolar output voltage referenced to ground i..

1.64 €

±12V / 100mA Power Supply - HK1033

This device is a bipolar power supply designed to provide symmetrical ±12 V DC voltage for electronic circuits requiring dual supply rails. The power supply consists of a rectifier, filter, and a para..

1.94 €

Electronic Melody Doorbell - HK1034

This device is an electronic melody doorbell based on the NE555 integrated circuit, operating as a dual-frequency generator. One tone is generated when the button is pressed, and a second tone is gene..

2.17 €

Microphone Preamplifier - HK1035

This device is a transistor-based microphone preamplifier designed for use with an electret microphone connected directly to the circuit input. The preamplifier increases the microphone signal level t..

1.51 €

Transistor Stereo Tone Control - HK1036

This transistor-based stereo tone control allows both boosting and attenuation of low and high audio frequencies, unlike passive tone control circuits which provide attenuation only. The circuit enab..

2.05 €

Stereo Preamplifier with Tone Control - HK1037

This stereo preamplifier with active tone control is easy to build while providing very good Hi-Fi class performance. The circuit allows independent boosting and attenuation of low and high frequencie..

2.35 €

Antenna Amplifier - HK1038

The antenna amplifier is designed to boost weak radio frequency signals in the VHF, FM, and CB bands. It is built around a single BF199 RF transistor and features a simple and reliable circuit design...

1.33 €

Four Time Relay Circuits - HK1040

Time relays are widely used in hobby electronics for controlling models, processes, and creating various timing effects. This kit includes four different time relay circuits assembled on a single expe..

2.43 €

Time Relay 0-160 Seconds - HK1041

The time relay is based on the NE555 timer (U1) configured as a monostable multivibrator. Using button B2, the relay is reset and remains in standby mode. A single press of button B1 activates the rel..

2.91 €