The author made a DTMF digital display with reference to relevant information, and would like to share it with you.
The circuit principle is shown in the drawing. DTMF digital decoder IC1 adopts MT8870, the 2 pin of the chip is the IN signal input end, the external crystal of 7 and 8 feet is used as the clock oscillation end, the frequency of the clock oscillation circuit is 3.579545MHz, and the generated double audio signal is the high frequency group. There are 16 kinds of combined frequencies from 1209 Hz to 1633 Hz and low frequency groups from 697 Hz to 941 Hz. After the two-input signal input by the 2-pin is digitally operated, the four-digit binary code ABCD is outputted at the data output terminals 11, 12, 13, and 14 and a positive pulse signal is output as the latter stage by the 15-pin at the end of the decoding. The latch pulse of the circuit.
CD4511 is a seven-segment BCD latch decoding, driving the common cathode digital tube display, CD4511 7, 5, 6 feet for ABCD code input, 3 feet LT for test light, 4 feet BI for blanking feet, 5 feet LE is the latch control terminal, and pins 9-15 are used to drive the digital tube to display characters. The output terminal uses the R5-R12 current limiting resistor to make the LED digital tube display 0-9 digits. The digital tube adopts the common cathode type, and the 15th pin of IC1 outputs a positive pulse signal, which is used as the latching pulse of the latter stage circuit, and the base of VD1, R4 to VT1, so that the collector outputs a low level signal. When the pin 8 of IC2 has a low level signal, it can drive the digital tube to display characters. The displayed characters are the numbers 0-9.
I have used this decoded digital display for more than half a year. With the frequency meter and oscilloscope, it is convenient to adjust the dual audio frequency when repairing the radio.
Our products ranges:
LED aquarium lights for fish tanks,corals,saltwater tank,marine tank with reef,coral,sps,lps,fish,etc;
LED plant grow lights for agricultural lighting;
Our Coral Reef Led Aquarium Light is popular in led market,cause its elegant outlook and its high quality and competitive price.
Key Features
1.The lifespan is over 50000 hours,low maintenance costs.
2.Energy conservation,saving over 80% energy than the traditional HPS.
3.High light efficiency,90% of the light will be absorbed by the aquatic plants,while just 8%-10% to the HPS.
4.Build-in cooling system,could solve the heat dissipation excellently.
5.Built-in power supply, CE approved, No setup required, just simpler and safer plugs directly into AC85V-264V, no reflector & ballast needed.
Item Display
Convenient in using lights at the same time.
Package Include
1 X Free Hanging Kit
1X Free Power Cord
Quality Control systems and after-sales
All the lamps have passed strict quality examination and are packed carefully before shipping.In order that our customers get high quality lamps,we attach importance to every details.
Application
1. coral reef lighting,fish tank lighting,coral reef tank lighting
2. Aquarium Lighting ,aquarium art,aquarium shop,aquarim centre
3. fish bowl lighting,fish lighting,freshwater lighting,saltwater lighting
Our Company
Philizon Advantages
Professional: we are professional Led Grow Lights and Led Aquarium Light manufactuer here in China,you will get Professional and High quality LED Grow Lights and Coral Reef Led Aquarium Light from us and get good guarantee.
Cost-effective Price:we don`t have the lowest price,but the Coral Reef Led Aquarium Light you get from us really cost-effective,good quality & decent price.
Win-win situation:Long term business is our mission,we will provide good Coral Reef Led Aquarium Light and warming service to build a long-term business relationship with you
24/7 unlimted customer service: we are always here for you for your question,any question just email us or call us,we do our best to help you all the way.
Long term warranty: Don`t worry about the quality and we guarantee you 3years warranty for all the Led Plant Grow Light and coral reef led aquarium light.
Best buying experience: you will get the tiptop serive you have ever had,just have a try and you`ll see.
Trade Terms
Payment: T/T, L/C, Paypal, 30% deposits before production, 70% balance to be paid before deliverying(Western Union are welcome)
Sample will be delivered within 7 working days.
Discounts are offered based on order quanlityes.
MOQ:sample order are acceptable
Delivery ways:DHL,UPS,FedEx,TNT, door to door,by sea,by air,etc.
Philizon enjoys a high reputation in grow led lamp and led aquarium light fields throughout Europe and America,Philizon also insists on taking high technology to design the newest&best led grow light and aquarium light constantly as the market request. Our R&D team with more than 10 people has rich experience in appearance design, electronic structure,heat dissipation simulation analysis,optical lens design,light control system etc.Most of our hydroponics full spectrum Led Grow Lighting and Coral Reef Led Aquarium Light are private modules,we have 10 more design patent and utility model patent till now.
Warmly welcome to take a visit on our factory at any time and we will pick you up at the airport or hotel as you request.
Aquarium Led Light,Smart Led Aquarium Light,Smart Aquarium Light,Aquarium Led Light
Shenzhen Phlizon Technology Co.,Ltd. , https://www.philizon.com