diff --git a/figs/tf_amplifiers_comp.pdf b/figs/tf_amplifiers_comp.pdf index eb5cbdf..514be56 100644 Binary files a/figs/tf_amplifiers_comp.pdf and b/figs/tf_amplifiers_comp.pdf differ diff --git a/figs/tf_amplifiers_comp.png b/figs/tf_amplifiers_comp.png index 34085fa..34eb268 100644 Binary files a/figs/tf_amplifiers_comp.png and b/figs/tf_amplifiers_comp.png differ diff --git a/index.html b/index.html index c525ca7..0659788 100644 --- a/index.html +++ b/index.html @@ -3,7 +3,7 @@ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> - + Measurement of Piezoelectric Amplifiers @@ -31,27 +31,27 @@

Table of Contents

@@ -71,12 +71,12 @@ The piezoelectric actuator under test is an APA95ML from Cedrat technology. It contains three stacks with a capacitance of \(5 \mu F\) each that can be connected independently to the amplifier.

-
-

1 Effect of a change of capacitance

+
+

1 Effect of a change of capacitance

-
-

1.1 Cedrat Technology

+
+

1.1 Cedrat Technology

Load Data @@ -109,7 +109,7 @@ win = hann(ceil(0.1/Ts));

-
+

change_capa_cedrat.png

Figure 1: Effect of a change of the piezo capacitance on the Amplifier transfer function

@@ -117,8 +117,8 @@ win = hann(ceil(0.1/Ts));
-
-

1.2 PI

+
+

1.2 PI

piezo1 = load('mat/pi_505_high.mat', 't', 'V_in', 'V_out');
@@ -145,7 +145,7 @@ win = hann(ceil(0.1/Ts));
-
+

change_capa_pi.png

Figure 2: Effect of a change of the piezo capacitance on the Amplifier transfer function

@@ -154,12 +154,12 @@ win = hann(ceil(0.1/Ts));
-
-

2 Effect of a change in Voltage level

+
+

2 Effect of a change in Voltage level

-
-

2.1 Cedrat Technology

+
+

2.1 Cedrat Technology

hi = load('mat/cedrat_la75b_high_1_stack.mat', 't', 'V_in', 'V_out');
@@ -184,7 +184,7 @@ win = hann(ceil(0.1/Ts));
-
+

change_level_cedrat.png

Figure 3: Effect of a change of voltage level on the Amplifier transfer function

@@ -192,8 +192,8 @@ win = hann(ceil(0.1/Ts));
-
-

2.2 PI

+
+

2.2 PI

hi = load('mat/pi_505_high.mat', 't', 'V_in', 'V_out');
@@ -214,7 +214,7 @@ win = hann(ceil(0.1/Ts));
-
+

change_level_pi.png

Figure 4: Effect of a change of voltage level on the Amplifier transfer function

@@ -223,12 +223,12 @@ win = hann(ceil(0.1/Ts));
-
-

3 Comparison PI / Cedrat

+
+

3 Comparison PI / Cedrat

-
-

3.1 Results

+
+

3.1 Results

ce_results = load('mat/cedrat_la75b_high_1_stack.mat', 't', 'V_in', 'V_out');
@@ -240,13 +240,21 @@ pi_results = load('mat/pi_505_high.mat', 't', 'V_in', 'V_out');
 
Ts = 1e-4;
 win = hann(ceil(0.1/Ts));
 
-[tf_ce, f_ce] = tfestimate(ce_results.V_in, ce_results.V_out, win, [], [], 1/Ts);
-[tf_pi, f_pi] = tfestimate(pi_results.V_in, pi_results.V_out, win, [], [], 1/Ts);
+[tf_ce, f] = tfestimate(ce_results.V_in, ce_results.V_out, win, [], [], 1/Ts);
+[tf_pi, ~] = tfestimate(pi_results.V_in, pi_results.V_out, win, [], [], 1/Ts);
+

+
+ +

+We remove the phase delay due to the time delay of the ADC/DAC: +

+
+
angle_delay = 180/pi*angle(squeeze(freqresp(exp(-s*Ts), f, 'Hz')));
-
+

tf_amplifiers_comp.png

Figure 5: Comparison of the two Amplifier transfer functions

@@ -255,8 +263,8 @@ win = hann(ceil(0.1/Ts));
-
-

4 Impedance Measurement

+
+

4 Impedance Measurement

The goal is to experimentally measure the output impedance of the voltage amplifiers. @@ -278,13 +286,13 @@ From the two values of voltage, the internal resistor value can be computed:

-
-

4.1 Cedrat Technology

+
+

4.1 Cedrat Technology

R = 10;    % Resistive Load used [Ohm]
-V = 10.09; % Output Voltage without any load [V]
-Vp = 3.46; % Output Voltage with resistice load [V]
+V = 0.998; % Output Voltage without any load [V]
+Vp = 0.912; % Output Voltage with resistice load [V]
@@ -294,7 +302,24 @@ Vp = 3.46; % Output Voltage with resistice load [V] 
-19.162
+0.94298
+
+ + +
+
R = 47;    % Resistive Load used [Ohm]
+V = 4.960; % Output Voltage without any load [V]
+Vp = 4.874; % Output Voltage with resistice load [V]
+
+
+ +
+
R * (V - Vp)/Vp;
+
+
+ +
+0.8293
@@ -308,13 +333,13 @@ G_ce = 1/(1+Ri*C*s);
-
-

4.2 PI

+
+

4.2 PI

R = 10;    % Resistive Load used [Ohm]
-V = 10.35; % Output Voltage without any load [V]
-Vp = 4.14; % Output Voltage with resistice load [V]
+V = 1.059; % Output Voltage without any load [V]
+Vp = 0.828; % Output Voltage with resistice load [V]
@@ -324,7 +349,24 @@ Vp = 4.14; % Output Voltage with resistice load [V] 
-15
+2.7899
+
+ + +
+
R = 10;    % Resistive Load used [Ohm]
+V = 2.092; % Output Voltage without any load [V]
+Vp = 1.637; % Output Voltage with resistice load [V]
+
+
+ +
+
R * (V - Vp)/Vp
+
+
+ +
+2.7795
@@ -332,7 +374,7 @@ Vp = 4.14; % Output Voltage with resistice load [V]

Author: Dehaeze Thomas

-

Created: 2020-08-13 jeu. 17:11

+

Created: 2020-08-17 lun. 08:41

diff --git a/index.org b/index.org index aeb4889..8e7f065 100644 --- a/index.org +++ b/index.org @@ -315,16 +315,21 @@ Compute Coherence and Transfer functions Ts = 1e-4; win = hann(ceil(0.1/Ts)); - [tf_ce, f_ce] = tfestimate(ce_results.V_in, ce_results.V_out, win, [], [], 1/Ts); - [tf_pi, f_pi] = tfestimate(pi_results.V_in, pi_results.V_out, win, [], [], 1/Ts); + [tf_ce, f] = tfestimate(ce_results.V_in, ce_results.V_out, win, [], [], 1/Ts); + [tf_pi, ~] = tfestimate(pi_results.V_in, pi_results.V_out, win, [], [], 1/Ts); +#+end_src + +We remove the phase delay due to the time delay of the ADC/DAC: +#+begin_src matlab + angle_delay = 180/pi*angle(squeeze(freqresp(exp(-s*Ts), f, 'Hz'))); #+end_src #+begin_src matlab :exports none figure; ax1 = subplot(2, 1, 1); hold on; - plot(f_pi, abs(tf_pi), 'DisplayName', 'PI') - plot(f_ce, abs(tf_ce), 'DisplayName', 'Cedrat') + plot(f, abs(tf_pi), 'DisplayName', 'PI') + plot(f, abs(tf_ce), 'DisplayName', 'Cedrat') set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'log'); ylabel('Amplitude'); xlabel('Frequency [Hz]'); hold off; @@ -333,12 +338,12 @@ Compute Coherence and Transfer functions ax2 = subplot(2, 1, 2); hold on; - plot(f_pi, 180/pi*unwrap(angle(tf_pi))) - plot(f_ce, 180/pi*unwrap(angle(tf_ce))) + plot(f, 180/pi*unwrap(angle(tf_pi))-angle_delay) + plot(f, 180/pi*unwrap(angle(tf_ce))-angle_delay) set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin'); ylabel('Phase'); xlabel('Frequency [Hz]'); hold off; - ylim([-360, 0]); + ylim([-270, 90]); yticks(-360:90:90) linkaxes([ax1,ax2], 'x'); @@ -379,8 +384,8 @@ From the two values of voltage, the internal resistor value can be computed: ** Cedrat Technology #+begin_src matlab R = 10; % Resistive Load used [Ohm] - V = 10.09; % Output Voltage without any load [V] - Vp = 3.46; % Output Voltage with resistice load [V] + V = 0.998; % Output Voltage without any load [V] + Vp = 0.912; % Output Voltage with resistice load [V] #+end_src #+begin_src matlab :results replace value @@ -388,7 +393,20 @@ From the two values of voltage, the internal resistor value can be computed: #+end_src #+RESULTS: -: 19.162 +: 0.94298 + +#+begin_src matlab + R = 47; % Resistive Load used [Ohm] + V = 4.960; % Output Voltage without any load [V] + Vp = 4.874; % Output Voltage with resistice load [V] +#+end_src + +#+begin_src matlab :results replace value + R * (V - Vp)/Vp; +#+end_src + +#+RESULTS: +: 0.8293 #+begin_src matlab C = 5e-6; % Capacitance in [F] @@ -424,8 +442,8 @@ From the two values of voltage, the internal resistor value can be computed: ** PI #+begin_src matlab R = 10; % Resistive Load used [Ohm] - V = 10.35; % Output Voltage without any load [V] - Vp = 4.14; % Output Voltage with resistice load [V] + V = 1.059; % Output Voltage without any load [V] + Vp = 0.828; % Output Voltage with resistice load [V] #+end_src #+begin_src matlab :results replace value @@ -433,5 +451,18 @@ From the two values of voltage, the internal resistor value can be computed: #+end_src #+RESULTS: -: 15 +: 2.7899 + +#+begin_src matlab + R = 10; % Resistive Load used [Ohm] + V = 2.092; % Output Voltage without any load [V] + Vp = 1.637; % Output Voltage with resistice load [V] +#+end_src + +#+begin_src matlab :results replace value + R * (V - Vp)/Vp +#+end_src + +#+RESULTS: +: 2.7795