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Senior Design Team 181 Www.transtekinc.com

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Senior Design Team 181 www.transtekinc.com Team: • Ryan Williams (EE) • Jonathan Wolff (EE) • Damon Soto (EE) • Jason Meyer (EE) Advisor: Helena Silva (ECE) Trans-Tek Contacts: • Mark Bennett • Jeffrey Gladu • • • • • • • • • LVDT Background Current Oscillator/Demodulator Model Design Alternatives – Oscillator Design Alternatives – Demodulator Final Design Goals Progress Timeline Budget • Consists of a 3-part transformer • Secondary coils wired in subtractive configuration • Position of core determines output voltage • Linear relationship between core position and output voltage http://upload.wikimedia.org/wikipedia/commons/0/07/Lvdt_how.gif http://www.singer-instruments.com/sites/default/files/images/tutorials/how_lvdt_works_fig3.gif The LVDT housing will be extended to contain the circuitry. LVDT components: 1. Stainless Steel Tubing/housing (top) 2. LVDT pushrod (bottom left) 3. Core (bottom right) 4. LVDT Windings (middle) www.transtekinc.com www.transtekinc.com • Second part is the oscillator itself. • Hardware circuit that converts a DC signal to an AC signal. • Frequency of the oscillator is determined by a RC combination, looking for a range of 1.5 to 12.5 kHz. • Output voltage should be 1 VRMS. • Need to make an oscillator with almost no harmonic distortion. http://www.electronics-tutorials.ws/oscillator/osc22.gif • Third subpart is the amplifier. • Will take the output signal of the Oscillator portion and amplify the wave form. • Output voltage determined by a resistor, looking for 1 to 6 VRMS. Reference Signal DC Offset LVDT Output Microcontroller Remove DC Offset Readout Device Receive reference & output signals ADC Determine amplitude ratio Output DC signal (with offset) Calculate corresponding DC ouput Identify phase shift RIGID • Cheaper • More reliable • Thickness can vary Notice the small dimensions of the aluminum tubing. The extra space a flexible PCB would give is so small it is negligible. LVDT – Linear Variable Differential Transformer