Condenser Microphone These condenser microphones are widely used in electronic circuits to detect minor sounds or air vibrations which in turn are converted to electrical signals for further use. This condenser microphone has  two legs which are used to make electrical connection with the circuit. The two plates of the capacitor, which is the heart of the microphone, The diaphragm (inside the metal body) is a very thin film of conducting metal. It is deformable and elastic in nature. The diaphragm is pasted on a solid hollow ring which provides the necessary support to the diaphragm. The back plate is a thick solid perforated metallic plate. It is coated with a permanently charged electret material to eliminate the need of polarized power supply. These electrets are made by melting a dielectric material (like wax, plastic, etc) that contains polar molecules and solidifying them back in a strong electrostatic field. The polar molecules of the dielectric material are inclined towards the direction of the electrostatic field and create a permanent electrostatic bias in them. In the modern microphones, PTFE (Poly Tetra Fluoro Ethylene) plastic is used to form the electric material. The design of the holes plays a very vital role in reducing the air damping and mechanical thermal noise. The two plates have a small gap between them to allow the movements of diaphragm. A very fine thin film of plastic is placed between the two plates to provide electrical insulation. The diaphragm moves in the air gap between the plates with the slightest disturbance caused in the surrounding air pressure by the sound signal. If you want to use this condenser microphone in your project, for that you will need few essential components like batteries or power supply, IC, resistors and capacitors.

DC 6V To 30V One Way Relay Module Wide voltage power supply (6 - 30v), supports micro usb 5.0v power supply, easy to use. With emergency stop function (“stop” button) and reverse polarity protection which can avoid burning by reverse connection. It is 6-30V 1-Channel Delay Power Relay Module with Onboard Adjustable Timing Cycle Switches with Digital LED display It is mostly used in Home Automation Delay Timer Control Switch Module Timer Controller. The Module operates at Operating voltage range of 6-30V, also it supports micro USB 5.0V power supply. Output capability: Can control the device within DC 30V 5A or AC 220V 5A. It can be applied to many fields as there is a wide range of application. Operation Mode: P1: Trigger signal, the relay is on “OP” time, and then disconnect; Within the “OP” time, proceed as follows: P1.1: the signal is triggered again, invalid P1.2: the signal is triggered again, re-clocking P1.3: Signal has triggered again, the relay is disconnected, stop the clock; P-2: Trigger signal, after the “CL” time is off, the “OP” time is on. When the timing is completed, the replay will be disconnected; P3.1: Trigger signal, after the “OP” time is on, the “CL” time is off, then cycle the above actions. If trigger signal within the loop, the relay will be disconnected and stop the clock. The number of cycles ( “LOP “) can be set. P3.2: No need to trigger the signal after powering up, the “OP” time is on, the “CL” time is off, then cycle the above actions; The number of cycles ( “LOP “) can be set. P-4: Signal holding function. If the signal is triggered, timing is cleared, the relay remains on; when the signal disappears, the relay will be off when the “OP” time is over; if another signal is triggered during timing, timing will be cleared. How to choose the time interval: parameter Introduction: OP power over time, turn off time CL, LOP cycle times (1-999 times, “—” is unlimited cycle) In the selection of parameter set interface mode, and press the STOP button to select the time. (1)xxx. if the decimal point is in some place, the time interval is s-1 999 s (2)xx. x is the decimal place is ten, the time interval is 0.1 s 99.9 s- (3)x. x. x is the decimal point are all on, the time interval is 1 min-999 min How to set the parameter: First, make sure relay operation mode According to the operating relay mode, the main interface (power module will flash current operating mode; standard mode P1.1, then come into the main interface); long press SET key two seconds and then choose and enter selection interface mode; by pressing UP, DOWN key to choose the mode setting  (P1.1 ~ P4) After selecting the mode, press short SET to set the corresponding parameter, then the parameter you want to set will flash (OP power in time; CL power off time; LOP cycle times, “—” is unlimited cycle ); by UP, DOWN to set the parameter value, support long press (increase or decrease quickly) and press slightly (increase or decrease of 1 unit); after setting the parameter value by short press the STOP key to choosing decimal place; choose the time interval (corresponding time interval is 0.1 s-999 min); Short press SET to set the current mode next parameter, the process is the same as above After the setting mode parameter, press and hold the SET button then hold the current configuration mode will flash, then go back to the main interface; define success parameter main interface: when the relay does not work, it will show “000” (no decimal point); the operating state relay, the screen has a decimal point   Mode Select Interface: press and hold the SET key to enter; after setting, long-press the SET button back on the main interface Activate Relay Mode: NO: PO in power over time, the relay can be connected OFF: relay is not allowed to connect, when in the off state in short main interface press the STOP key to achieve turn ON and OFF, the current state will flash; then back to the main interface (this function is a function of a sudden stop, 1 key to turn off the relay) Sleep Mode: C-P Sleep mode: within 5 minutes, no operation; nixie tube will close auto display, and a function program well Note: Press and hold the STOP button for 2 seconds can achieve change from C-P to O-d; Current state will flash and then return to the main interface The relay contact is passive and electricity production; 1 channel has the control function on / off Package Includes: 1 x One Way Relay Module Specifications: Operating Voltage 5 – 36V Operating Current 50mA Maximum Operating Current 30 A Power 400W Dimensions (mm) 60 x 34 x 21 Weight (gm) 18

DTMF Decoder - GL Decodes DTMF audio signal to 4 bit binary TTL level output with LED indication. It also indicates outputs with LED. Can be used directly with microcontrollers to develop various DTMF related applications like remote monitoring, remote control, Caller ID, Auto Dialer, Remote Triggering etc. read more : DTMF DECODER: MADE IN INDIA Applications: Remote Control systems. Caller ID applications. FM receiver-based remote control. Remote control using a Mobile phone. Package includes: 1 x DTMF Decoder - GL Specifications: Operating Voltage 5/12V (DC/AC) Operating Current 100 mA. Weight 10g

FOFEK 24V-380V 40Amp DA Solid State Relay Module This is SSR-40DA Solid State Relay Module 3-32VDC/24-380VAC 40A. A solid-state relay (SSR) allows you to control high-current AC loads from lower-voltage DC control circuitry. Solid-state relays have several advantages over mechanical relays. One such advantage is that they can be switched by a much lower voltage and at a much lower current than most mechanical relays. Also, because there are no moving contacts, solid-state relays can be switched much faster and for much longer periods without wearing out. This particular SSR can switch current loads of up to 40A with a 3-32V DC input and a zero cross-trigger control method. Each one of these relays is equipped with four screw terminals (for use with ring or fork connectors) and a plastic cover that slides over the top of the relay to protect the terminals. Also, read our blog on Applications of Relay explaining 8 major applications, what is it, how does it works, its construction, and different types of relays. Package Include: 1 x FOFEK 24V-380V 40 DA Solid State Relay Module Specifications Brand  Fofek  DC-AC Loading current 40A Loading voltage 24 - 380V AC Control voltage 3 - 32V DC Dimensions  5 x 4 x 3cms  Weight  50 grams

Fofek SSR-40DA Input 3-32VDC Output 24-380VAC Solid State Relay Solid state relays have several advantages over mechanical relays. One of the advantages is that they can be switched by a lower voltage and at a lower current than most mechanical relays.  This is DC To AC SSR-40DA Solid State Relay Module 3-32VDC/24-380VAC 40A. A solid state relay (SSR) allows you to control high-current AC loads from lower voltage DC control circuitry. Solid state relays have several advantages over mechanical relays. One such advantage is that they can be switched by a much lower voltage and at a much lower current than most mechanical relays. Also, because there are no moving contacts, solid state relays can be switched much faster and for much longer periods without wearing out. This particular SSR can switch current loads of up to 40A with a 3-32V DC input and a zero cross trigger control method. Each one of these relays is equipped with four screw terminals (for use with ring or fork connectors) and a plastic cover that slides over the top of the relay to protect the terminals. Package Includes: 1 x Fofek SSR-40DA Input 3-32VDC Output 24-380VAC Solid State Relay Specifications: Model SSR-40 DA Input voltage 3-32VDC Output voltage 24-380VAC Output current 40A Weight (gm) 106

Fotek Solid State Relay SSR-25DA 25A This is DC To AC SSR-25DA Solid State Relay Module 3-32VDC/24-380VAC 25A. A solid-state relay (SSR) allows you to control high-current AC loads from lower voltage DC control circuitry. Solid-state relays have several advantages over mechanical relays. Solid-state relays have several advantages over mechanical relays. This particular SSR can switch current loads of up to 25A with a 3-32V DC input and a zero cross trigger control method. Each one of these relays is equipped with four screw terminals (for use with ring or fork connectors) and a plastic cover that slides over the top of the relay to protect the terminals. Also check Fotek SSR-40DD Input 3-32VDC Output 5-60VDC Solid State Relay. The relay allows you to control high-current AC loads with a lower voltage DC control circuit. It has a 3-32V DC input and a 5-60V DC output.  Package Includes: 1 x 25DA Solid State Relay 25DA Solid State Relay Specifications Brand  Fotek Relay Type  Solid State Relay  Operating Voltage 3-32V Dimensions  60 x 45 x 24 mm Weight  100 grams (approx)

4 Channel 12V ULN2003 based Relay Board Relay board module is used for controlling higher current loads from your microcontroller development board, PC parallel port or Arduino Uno. This board has four (4) on-board relay which can switch up to 7Amps. Relays terminals (C, NC, NO) are accessible through screw terminals which makes wiring up the board very easy. The relay is safely driven by ULN2003 IC hence your input device, such as Arduino, is protected from the relay circuit and IC will further protect your microcontroller from relay kickback. This is a 12V 4-Channel Relay interface board which can be controlled directly by a wide range of microcontrollers such as Arduino, AVR, PIC, ARM, 8051 and so on. It can control both AC and DC appliances such as Solenoids, Motors, lights, fans, etc- High-quality screw terminals (Terminal Block) provided (C, NC, NO) for quick and easy connection- Input Signal Pin connected to Burg stick for easy accessibility- LED Status indicators to indicate the relay ON/OFF status.- Mounting holes provided Package Includes: 1 x 4 Channel 12V ULN2003 based Relay Board Specifications Power supply 12V (Vcc) Number of Channels  4  Colour  Multicolour  Dimensions  5 x 3 x 1 cms  Weight 5 grams

ISD1820 3-5V Voice Module Recording And Playback Module with Microphone and 0.5W Speaker The ISD1820 Recording Module Voice Board is the real easy way to add Voice Recording (and Playback) to your project. The Module can be operated directly by using the 3 Push-Buttons or with every microcontroller (ex. Arduino). A microphone is implemented directly on the board, and you can connect any 8 Ohm Speaker. Your recordings are saved even without power due to the non-volatile storage on the ISD1820. This module uses the ISD1820 voice record and playback IC to record a single voice message of up to 10 seconds in length. The recorded message is stored in its specialized analogue flash memory that will keep the message stored even when power is removed. The module includes an electret microphone to record your message and push buttons allow for record, partial playback, or full playback of the message. Header pins allow for easy interface to a microcontroller and playback can be controlled with just one digital pin. Key control recording and playback operation method: REC key: recording button, press and hold to record, release the button to stop recording; RLAYE key: trigger mode playback, click to play the current voice of the entire paragraph; PLAYL key: jog mode playback, press and hold to playback, release to stop playing; RPL jumper: loop play mode control, can be played circularly; FT jumper: through control, it allows the microphone voice directly to the speaker to playback. Method of operation: REC button: record button, you can press and hold the recording, release the button to stop recording; RLAYE key: trigger mode playback, press will play this whole speech; PLAYL key: jog mode playback, press and hold until playback, release to stop playback; RPL Jumper: loop mode control, loop playback; FT Jumper: direct control, microphone voice through the speaker can playback. Also check the ISD1820 Sound Voice Board Recording Module. It features the ISD1820 chip with an onboard microphone, allowing direct recording of approximately 10 seconds of voice. This recording/playback device offers true single-chip voice recording, non-volatile storage, and playback capabilities for 8 to 20 seconds. Package Includes: 1 x ISD1820 3-5V Voice Module Recording 1 x Playback Module with Microphone 1 x 0.5W Speaker Specifications: Chip ISD1820 Operating Voltage (VDC) 3V-5V. Loudspeaker 8 ohm, 0.5W Dimensions (LxWxH) 80 x 60 x 30 in mm

ISD1820 Sound Voice Board Recording Module The ISD1820 Sound/Voice Board Recording is 100% Brand new and high-quality Board ISD1820 chip with an Onboard microphone, you can direct recording of About 10 seconds voice recording. This voice record/playback device is based on the ISD1820 chip, which can record/playback multiple-message. It can offer true single-chip voice recording, non-volatile storage, and playback capability for 8 to 20 seconds. For the sampling rate of 3.2KHz, it can record for the total duration of 20 seconds. Package Includes: 1 x ISD1820 Sound Voice Board Recording Module Specifications: IC Chip ISD1820 Operating Voltage (VDC) 3 ~ 5 Dimensions 5.5 x 3.8cms  Weight  5 grams

JQX-15F(T90) Coil Voltage DC 24V 6 Pin Power Relay This is a JQX-15F (T90) 24VDC 6Pin 30A Power Relay. The relay is switched with the help of a small signal from a microcontroller like an Arduino. This relay can be used to drive 30A devices. It has an operating voltage of 24V DC and a max current capacity of 30A. This relay is of T90 type. It is an SPDT relay. It has 3 output terminals, NO, NC, and COM. It has two COM terminals. APPLICATIONS: Control Solenoids Motors Bulbs and Lamp Home Automation Projects Freewheeling diode to protect your microcontroller.  Package includes: 1 x JQX-15F(T90) Coil Voltage DC 24V 6 Pin Power Relay Specifications: Model JQX-15F(T90) NC Contact Rating 30A @ 240V AC / 28V DC NO Contact Rating 20A @ 240V AC / 28V DC Number Of Pins 6 Supply Voltage 24VDC Weight 20g