In this intriguing DIY project instructional exercise, we are going to fabricate a ‘ZN415 AM Radio’ by deploying the TDA2822M speaker IC. Therefore, the figure beneath shows a schematic of the respective radio circuit. Moreover, ZN415 or ZN415E is an AM radio IC fabricated in the 8-pin DIL package. Hence, the IC contains a total top-notch AM signal collector built inside it and requires just a few outer components, and all the components are easily accessible in the market.
All the convoluted hardware like the RF indicator circuit, RF enhancer circuit, the auto gain control circuit (AGC) , and so forth are already inbuilt inside the IC. Therefore, you can easily fabricate a simple, high-quality, and sensitive AM receiver circuit using this IC. However, this IC works along with a bunch of resistors and capacitors.
ZN415E IC
The ZN415E IC is a modernized variant of the ZN414 IC, the interior circuit and affectability of both these ICs are approximately the same. The main distinction between the two is the sound yield. The redesigned adaptation ZN415E contains an 18 DB support stage to expand the sound yield to drive earphones and small speakers directly.
There are likewise other comparable adaptations of ZN414 IC that are accessible like MK484, and TA7642 with comparable performance. For additional subtleties see Radio and RF Circuits Section on our website.
Hardware Components
The following components are required to make AM Radio Amplifier Circuit
| S.no | Components | Value | Qty |
|---|---|---|---|
| 1 | RF Detector IC | ZN415 | 1 |
| 2 | IC | TDA2822M | 1 |
| 3 | Diode | 1N4148 | 1 |
| 4 | Coil | 55 turns | 1 |
| 5 | Speaker | 8 ohms | 1 |
| 6 | Variable Capacitor | 500pF | 1 |
| 7 | Capacitor | 0.01µF, 0.1µF, 100nF, 100µF, 10µF, 220µF | 3, 2, 2, 1, 1, 1 |
| 8 | Resistor | 4.7Ω, 3.3Ω, 10KR | 2, 1, 1 |
| 9 | Battery | 9 Volts | 1 |
TDA2822M Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of TDA2822
AM Radio Amplifier Circuit
Working Explanation
The circuit above mentioned is a full-fledge AM radio circuit utilizing ZN415 IC along with TDA2822M IC to drive the 8-ohm speaker. The RF signal is amplified with the help of ZN415 IC which is further proceeding to 1N4148 diode which converts the input signal into DC. Moreover, this amplified DC is further passed through the TDA2822 speaker IC which drives the speaker. However, the inductor Coil L1 has 55 turns which are composed of 0.315mm enameled copper wire wound on a 10mm x 100mm long ferrite rod. Furthermore, you can likewise experiment with some other AM radio coils as well for good performance.
Features
- Good audio output
- High sensitivity
- Inexpensive and economical
- Low input power consumption
