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NEWSCIENCENEWSCIENCENEWSCIENCE Throttle Control If you have a throttle position sensor, you should be able to access the signal from the sensor itself or from the computer connector. This signal is input to the cir- cuit as the primary control (i.e., throttle level = pulse width = vapour rate). If you don't have such a signal available, you will have to rig a rotary POT (variable resistor) to the gas linkage (i.e., coupled to something at the gas pedal or throttle cable running to the carb or Fl). If you make the attachment at the carb/Fl, be sure to use a POT that can handle the engine temp cycles. Don't use a cheap POT; get one rated for long life and mechanical wear. Mount it securely to something sturdy and stationary that will not fall apart when you step on the gas. get into the specs for each IC you use, to ensure you connect the right pins to the right wires to control the frequency and pulse width. You can use spare sockets to try out different discrete component values. Just keep the ones that are spec-compatible in the circuit, and get the job done. You crank up the throttle signal and put more electrical energy (fatter pulses) into the electrodes. Verify you can get 10% duty on the scope (2-100 sec on the hori- zontal time-base). Your averaging DVM will display the 90%-10% DC voltage across the output transistor (Vce or Vds or output to ground). Set and connect DVM in the supply current and measure 0.5—-5 amps, without blowing the DVM fuse. Now verify that you got every- thing you wanted. Verify your wiring connections using your DVM as a continuity detector. Check your wiring, one at a time, and yellow-line your final schematic as you go. You can best use board-mount miniature POTs for anything you want to set and forget. The LEDs are there to give you a quick visual check of uulses] normal versus abnormal operation ut of your new creation. es Control Range The full throttle range (idle to max) must control the vapour rate, i.e. pulse width (duty). The resistor values at the throttle signal must allow the throttle signal volt- age, say a 1-4 volt swing, to drive the vapour rate. You will be using this voltage swing to generate a 10% on ‘square’ pulse. The patent implies using a ‘resonant’ pulse in the 10-250 KHz frequency range, but it is not explicitly stated so. In this circuit, you will simply tune to whatever frequency makes the most effi- cient vapour conversion. You will have to Figure 4 (Revised) — univen 100k auth [24 switch Carburettor/Fuel Injector t2vpc Connection a cosose ; te : ‘naaen Figure 2 also shows that fittings , % are required to the carburettor/fuel oscillator injector. There are ready-made frequency Cth Gipswiteh ground kits (such as by Impco) available adjust 2k, tk : = for making your pressure fittings to the carburettor or fuel injector, Otu -1u .03u 3300pt u-tu.03u ° as the case may be. You will nec- +12VDC _ essarily be sealing the built-in S T Ot >) pressure vents and making a one-way air \_/ gauge intake. on The copper mesh comprises the OL \cht ‘inadvertent backfire’ protection fae spark plug —e ) gauge for the reaction chamber. Make sensor —_~ sure that all vapour/duct junctions HOU /tank level are airtight and holding full pres- <_/ gauge sure without leakage. _ Your new 'system' is considered chamber Het ) gauge level successful and properly adjusted level t = _/ gauge when you get the full power range sensor T at lower temperature and mini- mum vapour flow without blow- ing the pressure safety valve. 100k pump detector owl Monitoring with CHT or EGT ground Monitor your engine tempera- C * + ture with the CHT (cylinder head temp) or EGT (exhaust gas temp) Monitoring with CHT or EGT Monitor your engine tempera- ture with the CHT (cylinder head temp) or EGT (exhaust gas temp) 50 ¢ NEXUS APRIL — MAY 2002 WWW.NeXU smagazi ne.com