それで新たに基板つくり部品集めと言うことになったのですが、74HC04を手配したとのこと。水晶発振回路などではHC／HCUどちらも使えたような気がしましたが、フランクリン発振回路ではどうでしょうか。
To gather the devices for the new PCB there happened mistaken to order HC04. I wonder to be able to use HC04 as same as HCU04 and I checked operation on LTspice as below.
const int OUT_PIN = A3; //Changed for LCD Keypad Shield used
const int IN_PIN = A1; //Changed for LCD Keypad Shield used
//Capacitance between IN_PIN and Ground
//Stray capacitance is always present. Extra capacitance can be added to
//allow higher capacitance to be measured.
const float IN_STRAY_CAP_TO_GND = 24.48; //initially this was 30.00
const float IN_EXTRA_CAP_TO_GND = 2.0; // tuned
const float IN_CAP_TO_GND = IN_STRAY_CAP_TO_GND + IN_EXTRA_CAP_TO_GND;
const int MAX_ADC_VALUE = 1023;
//LCD Keypad Shield is used
#include
LiquidCrystal lcd( 8, 9, 4, 5, 6, 7);
void setup()
{
pinMode(OUT_PIN, OUTPUT);
//digitalWrite(OUT_PIN, LOW); //This is the default state for outputs
pinMode(IN_PIN, OUTPUT);
//digitalWrite(IN_PIN, LOW);
void loop()
{
//Capacitor under test between OUT_PIN and IN_PIN
//Rising high edge on OUT_PIN
pinMode(IN_PIN, INPUT);
digitalWrite(OUT_PIN, HIGH);
int val = analogRead(IN_PIN);
//Clear everything for next measurement
digitalWrite(OUT_PIN, LOW);
pinMode(IN_PIN, OUTPUT);
I thought that the bread board was no use for RF experiment because of its stray capacitor and inductance.
According with several OMs' blogs, they used it for RF circuit.
Prior to use the bresd board, I checked the stray capacitance and inductsnce for the bread board clip terminals.
I used the 50ohm resister loaded jig for measuring the stray capacitance and inductance with nano VNA.
リード線使い治具をブレッドボード隣同士に接続、クリップ反対側では隣同士をショートします。クリップ往復のインダクタンスがわかるはず。
I connected nano VNA with the breadbosrd neighboring clipa. And I shorted on he other side of clips.
The connection with the breadboard
お隣配線板との容量、配線板の端と反対側端とのインダクタンス。
Within the bread board there are alligning a number of the clips as below.
BB OPEN
It is the capacitance bedween the neighbour clips.
This time I would like to use a toroidal core for the trial making of an anntena . There are a number of cores in my junk box and I shall identify an adequate one from those. I used the Arduino LC meter and nano VNA to measure the inductance of coils used those cores.
The Arduino LC meter is good to measure the small coil inductance as several decade of nH. There is several error number by the jig and intrinsic circuit. However the gotten value is similar with gotten value by nanoVNA. The nano VNA is cooler than LCM because of measuring depending upon the frequency .
The result of this experiment I found #7（Estimated T25＃6） sample being suitable for my next trial.
The list of the measured coils wounded on cores The jig for nano VNA useThe coils
There are the result of nano VNA meassured. S-parameter trasing shape may be dependent on its core material's nature.
Thia is bare coil.
The bare coil
This is the result for FB-101 ferrite core coil.
FB-101
This is thr result for the carbonol iron dust core.
>The carbonil iron core<
I'm trying LC meter of Franklin oscillator by Arduino. I had made PCB and assembled it. I estimated the cause of measuring instability.
Franklin oscillator is based on A-type amplifier on sharrow biassing unlike the Colpitts or Hartley oscillator. By LTspice simulation, .tran result reported slowly winding up of oscillation.
Accordingly, I reedited the sketch of Arduino to take some timing between parameter switching chances.
I will introduce how to operate the LC meter on YOUTUBE.
If you are interested in this circuit, you can purchase the bare PCB from PCBWAY as below.
At first I made LC meter with PIC MPU, and I diverted it into Arduino environment recently. I made up PCB.
This time I confirmed the operation of Franclin oscillator by 74HCU04.
Edit→SPICE Directiveで呼出せるようSPICEdirective指定する。(74hcu04.asyが74hcu04のシミュレーションデータを呼び出す時に参照。)
Set SPICEdirective of .lib 74hc.lib to call up.
.lib 74hc.lib
