Quizmaster
radio-linked!
Published in issue 306, January 2002
The Quizmaster described here is a four-player version with an extra player to operate the ‘box’ and to ask the questions etc. No wiring required between the player and quizmaster desks!Knowledge-based quizzes of the ‘University Challenge’ variety are extremely popular, and have spawned many derivates that can be seen on TV every day. Where many people would be perfectly capable of organizing a quiz, persuading players and a quizmaster to participate, drawing up a list of questions (geared to the contestants’ specific interest or level of education) and arrange a suitable venue, alas, building a ‘machine’ to detect the first key press, display the score, etc. often poses insurmountable problems. The present design should be easy to build by anyone with reasonable skills in DIY electronics.
Transmitter Resistors: R1 = 8-way 10kOhm SIL array R2 = 100kOhm R4..R7 = 10kOhm R3 = 1MOhm Semiconductors: IC1 = HT12E (Farnell # 562415) IC2 = AM-RT4-433 (RF Solutions)* Miscellaneous: K1-K4= jack socket, 2.5mm, mono, PCB mount S1-S4 = pushbutton (external), 1 make contact S5 = on/off switch S6 = 8-way DIP switch BT1 = 3-V battery with holder (or 2 off AA/AAA battery) Receiver Resistors: R1 = 8-way 10kOhm SIL array R2 = 68kOhm R3-R7,R22 = 10kOhm R8-R11= 5kOhm 6 R21 = 220Ohm R12-R18 = 150Ohm R19 = 100kOhm R20 = 470Ohm R23 = 47Ohm R24 = 240kOhm R25-R28=470Ohm Capacitors: C1,C2 = 10µ F 16V C3-C6 = 100nF Semiconductors: D1 = 1N4001 D2-D6 = LED, green, 5mm dia. IC1 = HT12D (Farnell # 563250) IC2 = PIC17C44-16/P, programmed, order code 010030-41 IC3 = 74LS245 IC4 = ULN2803AP (Farnell # 3187032) IC5 = 7805 IC6 = UM3561 (UMC) (Rapid Electronics # 82-0704, tel. 01206 751166) IC7 = AM-HRR3-433 (RF Solutions) * LD1-LD4= 2-digit 7-segment LED display, common cathode, e.g., Kingbright DC56-11EWA T1-T4,T6 = BC548 T5=BC327 Miscellaneous: K1 = mains adaptor socket, PCB mount S1,S2,S3= pushbutton, 1 make contact, type CTL3 (Multimec) or DR-6 S4 = 3-way 1-pole switch S5 = 8-way DIP switch LS1 = 64Ohm loudspeaker PCB, order code 010030-1 (combined board for receiver and transmitter) * 433 MHz transmitter/receiver modules available as a pair from Maplin, order code VY48C.
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Please note. In view of the complexity of international markets, Elektor cannot guarantee the availability of components for this project.
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