// script for operating a toggle pushbutton switch
var switch_off = new Image();
switch_off.src = "gifs/red_button_up.gif";
var switch_on = new Image();
switch_on.src = "gifs/red_button_dn.gif";
var rled_off = new Image();
rled_off.src = "gifs/red_off.gif";
var rled_on = new Image();
rled_on.src = "gifs/red_on.gif";

var switch_state = 0;
var output_no = 0;

function not_toggle(){
//
if (switch_state == 0 )
{
switch_state=1;
document.images.red_btn.src = switch_on.src;
document.images.power_led.src = rled_on.src;
rebuild_all()
power_on();
}
else
{
switch_state=0;
document.images.red_btn.src = switch_off.src;
document.images.power_led.src = rled_off.src;
}
//end
}

//script for 555 flasher circuit
var gled_off = new Image();
gled_off.src = "gifs/green_off.gif";
var gled_on = new Image();
gled_on.src = "gifs/green_on.gif";
var yled_off = new Image();
yled_off.src = "gifs/yellow_off.gif";
var yled_on = new Image();
yled_on.src = "gifs/yellow_on.gif";

var ra_value = 5000; //4.7K Ra Value
var rb_value = 100000; //100K Rb value

var ct_value = 0.000001; //1uF Ct value
//var period_555 =1000*(((ra_value+(2*rb_value))*ct_value)/1.44);
//period t = 1/f of the pin 3 of 555 1/frequency f=1.44/(Ra+2(Rb))Ct
var charge_t = 1000*(0.693*(ra_value + rb_value)*ct_value);
//charge time is t1 = 0.693(Ra + Rb)Ct the output is high.
var discharge_t = 1000*(0.693*(rb_value)*ct_value);
//discharge time is t2 = 0.693(Rb*Ct) the output is low.
var period_t = (charge_t+discharge_t)/1000;   //as charge_t and discharge_t was in mS
var freq_h = 1/period_t;
var duty_c = 100*((discharge_t/1000)/period_t); //as discharge_t was in mS


function power_on() {
document.images.lo_led.src = gled_off.src;
document.images.hi_led.src = yled_on.src;
window.setTimeout('turn_off()',charge_t);
//end
}


function turn_on() {
document.images.lo_led.src = gled_off.src;
document.images.hi_led.src = yled_on.src;
window.setTimeout('turn_off()',charge_t);
//end
}

function turn_off() {
if (switch_state == 1)
{
document.images.lo_led.src = gled_on.src;
document.images.hi_led.src = yled_off.src;
window.setTimeout('turn_on()',discharge_t);
}
else
{
document.images.lo_led.src = gled_off.src;
document.images.hi_led.src = yled_off.src;
}
//end
}

//the below code for a pot for Ra resistor
var ra_pot=5;
var range_ra=1000;
function dec_ra(speedy) {
if (ra_value > 5000) {     //limit to 4.7K or discharge pin 7 transistor goes.
ra_pot = ra_pot-(1*speedy);
if (ra_pot < 1){
ra_pot=1;
}
ra_value = ra_pot*range_ra;
}
rebuild_all();
document.ra_set.ra_dsp.value = ra_pot;
//end
}

function inc_ra(speedy) {
if (ra_value < 10000000) {      //limit to 10M due to leakage
ra_pot = ra_pot+(1*speedy);
ra_value = ra_pot*range_ra;
}
rebuild_all();
document.ra_set.ra_dsp.value = ra_pot;
//end
}

function rebuild_all() {
charge_t = 1000*(0.693*(ra_value + rb_value)*ct_value);
discharge_t = 1000*(0.693*(rb_value)*ct_value);
var period_t = (charge_t+discharge_t)/1000;   //as charge_t and discharge_t was in mS
var freq_h = 1/period_t;
var duty_c = 100*((discharge_t/1000)/period_t); //as discharge_t was in mS
document.freq_f.freq.value =  freq_h;
document.period_f.period.value =  period_t;
document.duty_f.duty.value =  duty_c;
//end
}

//the below code for a pot for Rb resistor
var rb_pot=100;
var range_rb=1000;
function dec_rb(speedy) {
if (rb_value > 5000) {     //limit to 4.7K or discharge pin 7 transistor goes.
rb_pot = rb_pot-(1*speedy);
if (rb_pot < 1){
rb_pot=1;
}
rb_value = rb_pot*range_rb;
}
rebuild_all();
document.rb_set.rb_dsp.value = rb_pot;
//end
}

function inc_rb(speedy) {
if (rb_value < 10000000) {      //limit to 10M due to leakage
rb_pot = rb_pot+(1*speedy);
rb_value = rb_pot*range_rb;
}
rebuild_all();
document.rb_set.rb_dsp.value = rb_pot;
//end
}


//the below code for a variable Ct timing cap
var ct_pot=1.0;
var ct_range=1000000;
function dec_ct(speedy) {
if (ct_pot > 1) {     //limit to 1nF due to parasitics.
ct_pot = ct_pot-(1*speedy);
if (ct_pot < 1){
ct_pot=1;
}
ct_value = ct_pot/ct_range;
}
rebuild_all();
document.ct_set.ct_dsp.value = ct_pot;
//end
}

function inc_ct(speedy) {
if (ct_pot < 1000) {      //limit to 1000uF due to leakage errors.
ct_pot = ct_pot+(1*speedy);
ct_value = ct_pot/ct_range;
}
rebuild_all();
document.ct_set.ct_dsp.value = ct_pot;
//end
}

function range_sel() {
ct_range =  document.ct_set.cap_range.value;
ct_value = ct_pot/ct_range;
rebuild_all();
//end
}

function rb_range() {
range_rb =  document.rb_set.range_rb.value;
rb_value = rb_pot*range_rb;
rebuild_all();
//end
}

function ra_range() {
range_ra =  document.ra_set.range_ra.value;
ra_value = ra_pot*range_ra;
rebuild_all();
//end
}