{"id":2148,"date":"2023-11-27T21:53:27","date_gmt":"2023-11-27T21:53:27","guid":{"rendered":"https:\/\/simulide.com\/p\/mesure-pulses-per-minut__df331\/"},"modified":"2024-02-12T04:03:29","modified_gmt":"2024-02-12T04:03:29","slug":"mesure-pulses-per-minut__df331","status":"publish","type":"post","link":"https:\/\/simulide.com\/p\/mesure-pulses-per-minut__df331\/","title":{"rendered":"MEASURE PULSES PER MINUTE__(DF331)"},"content":{"rendered":"

PURPOSE.<\/strong> <\/span><\/span><\/span><\/h3>\n

The objective of this project is to count pulses in one minute<\/strong>. The measurement of each minute needs to be activated manually. If the signal is regular, the number of pulses will be the same between minutes.<\/span><\/span><\/span><\/p>\n

There are two counting modes:<\/span><\/span> <\/span><\/p>\n

a) Counting in one minute.<\/span><\/span><\/strong> This measurement gives complete precision<\/strong> but requires a time of one minute to obtain the result.<\/span><\/span>
b) Counting in 6 seconds.<\/span><\/span><\/strong> In this mode the measurement is obtained much earlier but with less precision<\/strong><\/span><\/span>.<\/span><\/span><\/strong> This mode is useful for making estimates<\/strong>.<\/span><\/span><\/span><\/p>\n

The keystroke count is shown at all times on an eight-digit, 7-segment LED display without non-significant zeros on the left<\/strong><\/em> for greater reading comfort.<\/span><\/span><\/span><\/p>\n

USE.<\/strong><\/span><\/span><\/span><\/h3>\n
Connect the digital signal to be measured to the input IN<\/strong>, then press <P><\/strong> (PULSES) so that the signal goes to the counter and it begins to increase the value at the speed of the input signal frequency. If this button is ON<\/strong>, the green LED<\/strong> on its right lights up blinking.<\/span><\/span><\/span>\"\"<\/a><\/div>\n
The counter has two measurement modes depending on the position of the <F><\/strong> (FAST) switch:
<\/span><\/span><\/span><\/h5>\n

a) <F>\u00a0<\/span><\/span> OFF LINE.<\/strong> (The counter will need one minute<\/strong> to obtain the measurement. The yellow LED<\/strong> on the right will be OFF<\/strong> in this position.
<\/span><\/span><\/span>b) <F> CONNECTED<\/strong>.<\/span><\/span> The counter will run for six seconds<\/strong>.<\/span><\/span> The result is obtained more quickly but with less precision.<\/span><\/span> The number that appears on the screen will always have the digit of the units at zero, this is due to the decrease in precision. Example: if the display shows 14560, the real pulses\u00a0<\/span><\/span><\/span>could be between 14560 <\/span><\/span>and 14569 pulses <\/span><\/span><\/span>per minute.<\/span><\/span> The\u00a0 LED<\/strong> will be ON<\/strong> in this position.<\/span><\/span> <\/span><\/p>\n

At the bottom left is the “TIME ADVANCE”<\/strong>.<\/span><\/span> Here six LEDs show the elapsed measurement time in a “curtain”<\/strong> format.<\/span><\/span> It will move to the left at a speed of 10 seconds per LED<\/strong> at the one minute measuring position and 1 second per LED<\/strong> at the 6 second measuring position. <\/span><\/span><\/span>When the measurement time has elapsed, the display will stop<\/strong> counting showing the final value of pulses, at this time the \u201cTIME ADVANCE\u201d<\/strong> LEDs will take the pattern: 101101<\/strong> as the end of counting signal.<\/span><\/span><\/span><\/p>\n

Pressing the <R><\/strong> button clears the counter and the process begins again.<\/span><\/span> The counting does not start automatically.<\/span><\/span><\/span><\/h6>\n

DIAGRAM.<\/strong> <\/span><\/span><\/span><\/h3>\n

The following figure shows the circuit diagram<\/strong> that makes up the pulses per minute counter.<\/span><\/span> Its functional parts are described below:<\/span><\/span><\/span><\/p>\n

\"\"<\/a><\/p>\n

The pulse counter<\/strong>:<\/span><\/span><\/span><\/h6>\n
The pulse count is shown on an eight-digit 7-segment type display<\/strong>, which can reach up to 99999999<\/strong>. Each of these digits are separate units that work here in BCD (Binary Coded Decimal)<\/strong>, therefore one digit<\/span><\/span> It will have a 4-bit input numbered 1, 2, 4 and 8 corresponding to its binary weight.<\/span><\/span>
<\/span><\/h6>\n
These four inputs are connected to the outputs of 4 T-type flip-flops (toggle) that make up a 4-bit counter.<\/span><\/span> For this counter to operate in BCD there is a two-input AND gate, connected to weighted outputs 2 and 8, which resets the counter when the hexadecimal value “A” (1010)<\/strong> is reached.<\/span><\/span> This prevents all other Hexadecimal states above nine.<\/span><\/span> <\/span><\/h6>\n
The input to the binary time counter<\/strong> receives the clock signal selected by the <F> switch<\/strong> which can be 1 Hz for Slow<\/strong> Measurement Mode or 10 Hz for Fast<\/strong> Measurement Mode.<\/span><\/span><\/span><\/h6>\n
Erasing non-significant zeros on the left:<\/span><\/span><\/span><\/strong><\/h6>\n
At the output of the counters there is a 5-input NOR gate<\/strong> whose output turns off<\/strong> its own display whenever its four<\/span><\/span> inputs are at zero and in the previous digit<\/strong> there is a number other than zero<\/strong>, for this the fifth input takes the previous digit signal.<\/span><\/span> This device prevents a number zero preceded by another number other than zero from turning off the display of its own digit.<\/span><\/span> <\/span><\/h6>\n
Example<\/strong>: In 00078340 the three left zeros are turned OFF<\/strong>, but not<\/strong> the right zero.<\/span><\/span> <\/span><\/h6>\n
In order for each display to be turned off, “Show Enable Pin”<\/strong> must be checked in Porperties.<\/span><\/span>\u00a0 <\/span><\/h6>\n
The time counter<\/strong>:<\/span><\/span><\/span><\/h6>\n
A counter with 6 flip-flops counts up to 60, 3C in hexadecimal <\/strong>and 0011 11<\/strong>00 in binary. Therefore, an AND gate with four inputs connected to the four bits at 1 of the counter acts as a decoder to stop the counting and display the number of pulses reached.<\/span><\/span><\/span><\/h6>\n
TIME ADVANCE:<\/span><\/span> <\/span><\/strong><\/h6>\n
Since one minute of pulse counting is a relatively long waiting time, a 6-LED display<\/strong> has been provided to show the progress of time in the form of a curtain<\/strong>.<\/span><\/span><\/span><\/h6>\n
A ROM memory<\/strong> provides the pattern<\/strong> that will be displayed on the 6 LED strip to see the progress of time.<\/span><\/span> The following figure shows the content of this ROM<\/strong>, which is obtained by clicking on it in “Show Memory Table”<\/em><\/strong>.<\/span><\/span> In this table a progression of ones in binary will produce the LEDs turning on.<\/span><\/span> In the Last positions is the Value 2Dh<\/strong>, that is 0010 1101<\/strong> whose right 6 bits are the end of counting time signal pattern.<\/span><\/span><\/span><\/h6>\n
\"\"<\/a><\/h6>\n

The content of the ROM<\/strong> can be created<\/strong> in hexadecimal directly in the ROM in the “Show Memory Table”<\/strong> by writing the content in each position\u00a0 (0x3f for example) or loaded<\/strong> from a text file.<\/span><\/span> The content of the ROM can also be saved<\/strong> in a text file.<\/span><\/span><\/span><\/p>\n

All this hardware is concentrated in a subcircuit<\/strong> whose concept is discussed in the following section. This subcircuit will appear in Simulide as one more component that can be used in other schemes in which a pulse meter of this type is required.<\/span><\/span><\/span><\/p>\n

MISCELLANY.<\/span><\/span> <\/strong><\/span><\/h3>\n

The attached zip file typically includes:<\/span><\/span> <\/span><\/p>\n

1)<\/strong> Electrical diagram.<\/span><\/span> <\/span>
<\/span>2)<\/strong> “data”<\/strong> folder<\/span><\/span>. <\/span><\/p>\n

This data folder contains the subcircuits (custom) created by the author.<\/span><\/span> The presence of this folder<\/strong> is necessary for the execution of the project.<\/span><\/span>\u00a0<\/span><\/p>\n

SUBCIRCUIT:<\/strong> <\/span><\/span><\/span><\/h6>\n
A subcircuit It is a “custom”<\/strong> circuit that accumulates a set of Simulide base components to obtain a new <\/strong>or an adapted function<\/strong>. These subcircuits are treated by Simulide as another component of its own structure.<\/span><\/span>
<\/span><\/h6>\n
Subcircuits<\/strong> are very useful to create a component<\/strong> that does not exist in the simulide set, to compress a complete schematic<\/strong> in a single block and thus improve the complexity and compression of the final circuit where it is integrated or for any other function<\/strong> that you want to have available when making a schematic.
<\/span><\/span><\/span><\/h6>\n
The subcircuits must be properly incorporated in the “data” folder of simulide<\/strong>, in the “User Data” folder<\/strong> or in the “data” scheme folder<\/strong> that must be attached together with the schematic of the project itself.<\/span><\/span> Attaching the subcircuits to the Simulide “data” folder is not advisable because they can be lost with updates to it.<\/span><\/span> Attaching them in “User Data” is the correct thing to do.<\/span><\/span> Attaching it to the “data” folder of the diagram is necessary when it is shared.<\/span><\/span><\/span><\/h6>\n
Creating and locating a subcircuit<\/strong> is simple once you know the procedure that is explained in detail in the simulide tutorials<\/span><\/span><\/span>: https:\/\/simulide.com\/p\/subcircuits\/<\/a><\/strong><\/span><\/span><\/span><\/h6>\n
\u00a0<\/div>\n
* Communication with the author<\/strong>: Simulide\/User\/Messages\/Defran<\/span><\/span><\/span><\/div>\n<\/p>\n\n