diff --git a/content/zettels/cables.md b/content/zettels/cables.md
new file mode 100644
index 0000000..bacb566
--- /dev/null
+++ b/content/zettels/cables.md
@@ -0,0 +1,33 @@
++++
+title = "Cables"
+author = ["Thomas Dehaeze"]
+draft = false
++++
+
+Backlinks:
+
+- [Connectors]({{< relref "connectors" >}})
+
+Tags
+: [Connectors]({{< relref "connectors" >}})
+
+
+## Typical Cables {#typical-cables}
+
+- Coaxial cables
+- Twisted cables
+- Twisted shielded cables
+
+
+## Manufacturers {#manufacturers}
+
+| Manufacturers | Links | Country |
+|---------------|---------------------------------|-------------|
+| LEMO | [link](https://www.lemo.com/en) | Switzerland |
+
+
+## Software {#software}
+
+- [WireViz](https://github.com/formatc1702/WireViz) is a nice software to easily document cables and wiring harnesses
+
+<./biblio/references.bib>
diff --git a/content/zettels/charge_amplifiers.md b/content/zettels/charge_amplifiers.md
index 190f9eb..b1301b5 100644
--- a/content/zettels/charge_amplifiers.md
+++ b/content/zettels/charge_amplifiers.md
@@ -4,6 +4,10 @@ author = ["Thomas Dehaeze"]
draft = false
+++
+Backlinks:
+
+- [Signal Conditioner]({{< relref "signal_conditioner" >}})
+
Tags
: [Electronics]({{< relref "electronics" >}})
@@ -15,6 +19,24 @@ A charge amplifier outputs a voltage proportional to the charge generated by a s
This can be typically used to interface with piezoelectric sensors.
+## Basic Circuit {#basic-circuit}
+
+Two basic circuits of charge amplifiers are shown in Figure [1](#org9ffcf40) (taken from ([Fleming 2010](#orgaceef58))) and Figure [2](#org37bd87f) (taken from ([Schmidt, Schitter, and Rankers 2014](#org683b96e)))
+
+<a id="org9ffcf40"></a>
+
+{{< figure src="/ox-hugo/charge_amplifier_circuit.png" caption="Figure 1: Electrical model of a piezoelectric force sensor is shown in gray. The op-amp charge amplifier is shown on the right. The output voltage \\(V\_s\\) equal to \\(-q/C\_s\\)" >}}
+
+<a id="org37bd87f"></a>
+
+{{< figure src="/ox-hugo/charge_amplifier_circuit_bis.png" caption="Figure 2: A piezoelectric accelerometer with a charge amplifier as signal conditioning element" >}}
+
+The input impedance of the charge amplifier is very small (unlike when using a voltage amplifier).
+
+The gain of the charge amplified (Figure [1](#org9ffcf40)) is equal to:
+\\[ \frac{V\_s}{q} = \frac{-1}{C\_s} \\]
+
+
## Manufacturers {#manufacturers}
| Manufacturers | Links | Country |
@@ -28,4 +50,9 @@ This can be typically used to interface with piezoelectric sensors.
| Sinocera | [link](http://www.china-yec.net/instruments/signal-conditioner/multi-channels-charge-amplifier.html) | China |
| L-Card | [link](https://en.lcard.ru/products/accesories/le-41) | Rusia |
-<./biblio/references.bib>
+
+## Bibliography {#bibliography}
+
+<a id="orgaceef58"></a>Fleming, A.J. 2010. “Nanopositioning System with Force Feedback for High-Performance Tracking and Vibration Control.” _IEEE/ASME Transactions on Mechatronics_ 15 (3):433–47. <https://doi.org/10.1109/tmech.2009.2028422>.
+
+<a id="org683b96e"></a>Schmidt, R Munnig, Georg Schitter, and Adrian Rankers. 2014. _The Design of High Performance Mechatronics - 2nd Revised Edition_. Ios Press.
diff --git a/content/zettels/connectors.md b/content/zettels/connectors.md
index 36af82f..9c4dea8 100644
--- a/content/zettels/connectors.md
+++ b/content/zettels/connectors.md
@@ -5,7 +5,7 @@ draft = false
+++
Tags
-:
+: [Cables]({{< relref "cables" >}})
## Manufacturers {#manufacturers}
@@ -15,4 +15,13 @@ Tags
| LEMO | [link](https://www.lemo.com/en) | Switzerland |
| Fischer | [link](https://www.fischerconnectors.com/uk/en) | Switzerland |
+
+## BNC {#bnc}
+
+BNC connectors can have an impedance of 50Ohms or 75Ohms as shown in Figure [1](#org18575cd).
+
+<a id="org18575cd"></a>
+
+{{< figure src="/ox-hugo/bnc_50_75_ohms.jpg" caption="Figure 1: 75Ohms and 50Ohms BNC connectors" >}}
+
<./biblio/references.bib>
diff --git a/content/zettels/voltage_amplifier.md b/content/zettels/voltage_amplifier.md
index d378e25..6c796f4 100644
--- a/content/zettels/voltage_amplifier.md
+++ b/content/zettels/voltage_amplifier.md
@@ -6,6 +6,7 @@ draft = false
Backlinks:
+- [Signal Conditioner]({{< relref "signal_conditioner" >}})
- [Piezoelectric Actuators]({{< relref "piezoelectric_actuators" >}})
Tags
@@ -38,9 +39,9 @@ Tags
The piezoelectric stack can be represented as a capacitance.
-Let's take a capacitance driven by a voltage amplifier (Figure [1](#orgbf6bfad)).
+Let's take a capacitance driven by a voltage amplifier (Figure [1](#org1213200)).
-<a id="orgbf6bfad"></a>
+<a id="org1213200"></a>
{{< figure src="/ox-hugo/voltage_amplifier_capacitance.png" caption="Figure 1: Piezoelectric actuator model with a voltage source" >}}
@@ -60,7 +61,7 @@ Thus, for a specified maximum current \\(I\_\text{max}\\), the "power bandwidth"
- Above \\(\omega\_{0, \text{max}}\\), the maximum current \\(I\_\text{max}\\) is reached and the maximum voltage that can be applied decreases with frequency:
\\[ U\_\text{max} = \frac{I\_\text{max}}{\omega C} \\]
-The maximum voltage as a function of frequency is shown in Figure [2](#org29f059d).
+The maximum voltage as a function of frequency is shown in Figure [2](#org5c9f5fc).
```matlab
Vpkp = 170; % [V]
@@ -74,7 +75,7 @@ C = 1e-6; % [F]
56.172
```
-<a id="org29f059d"></a>
+<a id="org5c9f5fc"></a>
{{< figure src="/ox-hugo/voltage_amplifier_max_V_piezo.png" caption="Figure 2: Maximum voltage as a function of the frequency for \\(C = 1 \mu F\\), \\(I\_\text{max} = 30mA\\) and \\(V\_{pkp} = 170 V\\)" >}}
@@ -110,7 +111,7 @@ This can pose several problems:
### Noise {#noise}
-Sources of noise in a system comprising a voltage amplifier and a capactive load are discussed in ([Spengen 2020](#orge9a57bd)).
+Sources of noise in a system comprising a voltage amplifier and a capactive load are discussed in ([Spengen 2020](#org0688a0e)).
Proper enclosures and cabling are necessary to protect the system from capacitive and inductive interferance.
@@ -122,13 +123,13 @@ The **input** impedance of voltage amplifiers are generally set to \\(50 \Omega\
The **output** (or internal) impedance of voltage amplifier is generally wanted small in order to have a small voltage drop when large current are drawn.
However, for stability reasons and to avoid overshoot (due to the internal negative feedback loop), this impedance can be chosen quite large.
-This is discussed in ([Spengen 2017](#orge194af0)).
+This is discussed in ([Spengen 2017](#orgfe834ca)).
## Bibliography {#bibliography}
-<a id="org892a333"></a>Fleming, Andrew J., and Kam K. Leang. 2014. _Design, Modeling and Control of Nanopositioning Systems_. Advances in Industrial Control. Springer International Publishing. <https://doi.org/10.1007/978-3-319-06617-2>.
+<a id="org624e57c"></a>Fleming, Andrew J., and Kam K. Leang. 2014. _Design, Modeling and Control of Nanopositioning Systems_. Advances in Industrial Control. Springer International Publishing. <https://doi.org/10.1007/978-3-319-06617-2>.
-<a id="orge194af0"></a>Spengen, W. Merlijn van. 2017. “High Voltage Amplifiers and the Ubiquitous 50 Ohms: Caveats and Benefits.” Falco Systems.
+<a id="orgfe834ca"></a>Spengen, W. Merlijn van. 2017. “High Voltage Amplifiers and the Ubiquitous 50 Ohms: Caveats and Benefits.” Falco Systems.
-<a id="orge9a57bd"></a>———. 2020. “High Voltage Amplifiers: So You Think You Have Noise!” Falco Systems.
+<a id="org0688a0e"></a>———. 2020. “High Voltage Amplifiers: So You Think You Have Noise!” Falco Systems.
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