//
// Written by Curtis Olson, started September 2002.
//
-// Copyright (C) 2002 Curtis L. Olson - curt@flightgear.org
+// Copyright (C) 2002 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
-// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
-#include <simgear/misc/exception.hxx>
+#include <cstring>
+
+#include <simgear/structure/exception.hxx>
#include <simgear/misc/sg_path.hxx>
+#include <simgear/debug/logstream.hxx>
+#include <simgear/props/props_io.hxx>
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include "electrical.hxx"
-ElectricalSystem::ElectricalSystem ()
+
+FGElectricalComponent::FGElectricalComponent() :
+ kind(-1),
+ name(""),
+ volts(0.0),
+ load_amps(0.0)
{
}
-ElectricalSystem::~ElectricalSystem ()
+
+FGElectricalSupplier::FGElectricalSupplier ( SGPropertyNode *node ) {
+ kind = FG_SUPPLIER;
+
+ // cout << "Creating a supplier" << endl;
+ name = node->getStringValue("name");
+ string _model = node->getStringValue("kind");
+ // cout << "_model = " << _model << endl;
+ if ( _model == "battery" ) {
+ model = FG_BATTERY;
+ amp_hours = node->getFloatValue("amp-hours", 40.0);
+ percent_remaining = node->getFloatValue("percent-remaining", 1.0);
+ charge_amps = node->getFloatValue("charge-amps", 7.0);
+ } else if ( _model == "alternator" ) {
+ model = FG_ALTERNATOR;
+ rpm_src = node->getStringValue("rpm-source");
+ rpm_threshold = node->getFloatValue("rpm-threshold", 600.0);
+ ideal_amps = node->getFloatValue("amps", 60.0);
+ } else if ( _model == "external" ) {
+ model = FG_EXTERNAL;
+ ideal_amps = node->getFloatValue("amps", 60.0);
+ } else {
+ model = FG_UNKNOWN;
+ }
+ ideal_volts = node->getFloatValue("volts");
+
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ // cout << " scanning: " << child->getName() << endl;
+ if ( !strcmp(child->getName(), "prop") ) {
+ string prop = child->getStringValue();
+ // cout << " Adding prop = " << prop << endl;
+ add_prop( prop );
+ fgSetFloat( prop.c_str(), ideal_amps );
+ }
+ }
+
+ _rpm_node = fgGetNode( rpm_src.c_str(), true);
+}
+
+
+float FGElectricalSupplier::apply_load( float amps, float dt ) {
+ if ( model == FG_BATTERY ) {
+ // calculate amp hours used
+ float amphrs_used = amps * dt / 3600.0;
+
+ // calculate percent of total available capacity
+ float percent_used = amphrs_used / amp_hours;
+ percent_remaining -= percent_used;
+ if ( percent_remaining < 0.0 ) {
+ percent_remaining = 0.0;
+ } else if ( percent_remaining > 1.0 ) {
+ percent_remaining = 1.0;
+ }
+ // cout << "battery percent = " << percent_remaining << endl;
+ return amp_hours * percent_remaining;
+ } else if ( model == FG_ALTERNATOR ) {
+ // scale alternator output for rpms < 600. For rpms >= 600
+ // give full output. This is just a WAG, and probably not how
+ // it really works but I'm keeping things "simple" to start.
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
+ if ( factor > 1.0 ) {
+ factor = 1.0;
+ }
+ // cout << "alternator amps = " << amps * factor << endl;
+ float available_amps = ideal_amps * factor;
+ return available_amps - amps;
+ } else if ( model == FG_EXTERNAL ) {
+ // cout << "external amps = " << 0.0 << endl;
+ float available_amps = ideal_amps;
+ return available_amps - amps;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "unknown supplier type" );
+ }
+
+ return 0.0;
+}
+
+
+float FGElectricalSupplier::get_output_volts() {
+ if ( model == FG_BATTERY ) {
+ // cout << "battery amps = " << amps << endl;
+ float x = 1.0 - percent_remaining;
+ float tmp = -(3.0 * x - 1.0);
+ float factor = (tmp*tmp*tmp*tmp*tmp + 32) / 32;
+ // cout << "battery % = " << percent_remaining <<
+ // " factor = " << factor << endl;
+ // percent_remaining -= 0.001;
+ return ideal_volts * factor;
+ } else if ( model == FG_ALTERNATOR ) {
+ // scale alternator output for rpms < 600. For rpms >= 600
+ // give full output. This is just a WAG, and probably not how
+ // it really works but I'm keeping things "simple" to start.
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
+ if ( factor > 1.0 ) {
+ factor = 1.0;
+ }
+ // cout << "alternator amps = " << amps * factor << endl;
+ return ideal_volts * factor;
+ } else if ( model == FG_EXTERNAL ) {
+ // cout << "external amps = " << 0.0 << endl;
+ return ideal_volts;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "unknown supplier type" );
+ }
+
+ return 0.0;
+}
+
+
+float FGElectricalSupplier::get_output_amps() {
+ if ( model == FG_BATTERY ) {
+ // cout << "battery amp_hours = " << amp_hours << endl;
+
+ // This is a WAG, but produce enough amps to burn the entire
+ // battery in one minute.
+ return amp_hours * 60.0;
+ } else if ( model == FG_ALTERNATOR ) {
+ // scale alternator output for rpms < 600. For rpms >= 600
+ // give full output. This is just a WAG, and probably not how
+ // it really works but I'm keeping things "simple" to start.
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
+ if ( factor > 1.0 ) {
+ factor = 1.0;
+ }
+ // cout << "alternator amps = " << ideal_amps * factor << endl;
+ return ideal_amps * factor;
+ } else if ( model == FG_EXTERNAL ) {
+ // cout << "external amps = " << 0.0 << endl;
+ return ideal_amps;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "unknown supplier type" );
+ }
+
+ return 0.0;
+}
+
+
+FGElectricalBus::FGElectricalBus ( SGPropertyNode *node ) {
+ kind = FG_BUS;
+
+ name = node->getStringValue("name");
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ if ( !strcmp(child->getName(), "prop") ) {
+ string prop = child->getStringValue();
+ add_prop( prop );
+ }
+ }
+}
+
+
+FGElectricalOutput::FGElectricalOutput ( SGPropertyNode *node ) {
+ kind = FG_OUTPUT;
+ load_amps = 0.1; // arbitrary default value
+
+ name = node->getStringValue("name");
+ SGPropertyNode *draw = node->getNode("rated-draw");
+ if ( draw != NULL ) {
+ load_amps = draw->getFloatValue();
+ }
+ // cout << "rated draw = " << output_amps << endl;
+
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ if ( !strcmp(child->getName(), "prop") ) {
+ string prop = child->getStringValue();
+ add_prop( prop );
+ }
+ }
+}
+
+
+FGElectricalSwitch::FGElectricalSwitch( SGPropertyNode *node ) :
+ switch_node( NULL ),
+ rating_amps( 0.0f ),
+ circuit_breaker( false )
{
+ bool initial_state = true;
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ string cname = child->getName();
+ string cval = child->getStringValue();
+ if ( cname == "prop" ) {
+ switch_node = fgGetNode( cval.c_str(), true );
+ // cout << "switch node = " << cval << endl;
+ } else if ( cname == "initial-state" ) {
+ if ( cval == "off" || cval == "false" ) {
+ initial_state = false;
+ }
+ // cout << "initial state = " << initial_state << endl;
+ } else if ( cname == "rating-amps" ) {
+ rating_amps = atof( cval.c_str() );
+ circuit_breaker = true;
+ // cout << "initial state = " << initial_state << endl;
+ }
+ }
+
+ switch_node->setBoolValue( initial_state );
+ // cout << " value = " << switch_node->getBoolValue() << endl;
+}
+
+
+FGElectricalConnector::FGElectricalConnector ( SGPropertyNode *node,
+ FGElectricalSystem *es ) {
+ kind = FG_CONNECTOR;
+ name = "connector";
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ string cname = child->getName();
+ string cval = child->getStringValue();
+ // cout << " " << cname << " = " << cval << endl;
+ if ( cname == "input" ) {
+ FGElectricalComponent *s = es->find( child->getStringValue() );
+ if ( s != NULL ) {
+ add_input( s );
+ if ( s->get_kind() == FG_SUPPLIER ) {
+ s->add_output( this );
+ } else if ( s->get_kind() == FG_BUS ) {
+ s->add_output( this );
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "Attempt to connect to something that can't provide an output: "
+ << child->getStringValue() );
+ }
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "Can't find named source: "
+ << child->getStringValue() );
+ }
+ } else if ( cname == "output" ) {
+ FGElectricalComponent *s = es->find( child->getStringValue() );
+ if ( s != NULL ) {
+ add_output( s );
+ if ( s->get_kind() == FG_BUS ) {
+ s->add_input( this );
+ } else if ( s->get_kind() == FG_OUTPUT ) {
+ s->add_input( this );
+ } else if ( s->get_kind() == FG_SUPPLIER &&
+ ((FGElectricalSupplier *)s)->get_model()
+ == FGElectricalSupplier::FG_BATTERY ) {
+ s->add_output( this );
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "Attempt to connect to something that can't provide an input: "
+ << child->getStringValue() );
+ }
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "Can't find named source: "
+ << child->getStringValue() );
+ }
+ } else if ( cname == "switch" ) {
+ // cout << "Switch = " << child->getStringValue() << endl;
+ FGElectricalSwitch s( child );
+ add_switch( s );
+ }
+ }
+}
+
+
+// set all switches to the specified state
+void FGElectricalConnector::set_switches( bool state ) {
+ // cout << "setting switch state to " << state << endl;
+ for ( unsigned int i = 0; i < switches.size(); ++i ) {
+ switches[i].set_state( state );
+ }
}
-void
-ElectricalSystem::init ()
+
+// return true if all switches are true, false otherwise. A connector
+// could have multiple switches, but they all need to be true(closed)
+// for current to get through.
+bool FGElectricalConnector::get_state() {
+ unsigned int i;
+ for ( i = 0; i < switches.size(); ++i ) {
+ if ( ! switches[i].get_state() ) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+
+FGElectricalSystem::FGElectricalSystem ( SGPropertyNode *node ) :
+ name(node->getStringValue("name", "electrical")),
+ num(node->getIntValue("number", 0)),
+ path(node->getStringValue("path")),
+ enabled(false)
{
- config_props = new SGPropertyNode;
+}
+
- SGPath config( globals->get_fg_root() );
- config.append( fgGetString("/systems/electrical/path") );
+FGElectricalSystem::~FGElectricalSystem () {
+}
+
+
+void FGElectricalSystem::init () {
+ SGPropertyNode_ptr config_props = new SGPropertyNode;
+
+ _volts_out = fgGetNode( "/systems/electrical/volts", true );
+ _amps_out = fgGetNode( "/systems/electrical/amps", true );
+
+ // allow the electrical system to be specified via the
+ // aircraft-set.xml file (for backwards compatibility) or through
+ // the aircraft-systems.xml file. If a -set.xml entry is
+ // specified, that overrides the system entry.
+ SGPropertyNode *path_n = fgGetNode("/sim/systems/electrical/path");
+ if ( path_n ) {
+ if ( path.length() ) {
+ SG_LOG( SG_SYSTEMS, SG_INFO,
+ "NOTICE: System manager configuration specifies an " <<
+ "electrical system: " << path << " but it is " <<
+ "being overridden by the one specified in the -set.xml " <<
+ "file: " << path_n->getStringValue() );
+ }
+
+ path = path_n->getStringValue();
+ }
- SG_LOG( SG_ALL, SG_ALERT, "Reading electrical system model from "
- << config.str() );
- try {
- readProperties( config.str(), config_props );
- } catch (const sg_exception& exc) {
- SG_LOG( SG_ALL, SG_ALERT, "Failed to load electrical system model: "
+ if ( path.length() ) {
+ SGPath config = globals->resolve_aircraft_path(path);
+
+ // load an obsolete xml configuration
+ SG_LOG( SG_SYSTEMS, SG_WARN,
+ "Reading deprecated xml electrical system model from\n "
<< config.str() );
+ try {
+ readProperties( config.str(), config_props );
+
+ if ( build(config_props) ) {
+ enabled = true;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "Detected a logic error in the electrical system ");
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "specification file. See earlier errors for " );
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "details.");
+ exit(-1);
+ }
+ } catch (const sg_exception&) {
+ SG_LOG( SG_SYSTEMS, SG_ALERT,
+ "Failed to load electrical system model: "
+ << config.str() );
+ }
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_INFO,
+ "No xml-based electrical model specified for this model!");
+ }
+
+ if ( !enabled ) {
+ _amps_out->setDoubleValue(0);
}
- delete config_props;
}
-void
-ElectricalSystem::bind ()
-{
+
+void FGElectricalSystem::bind () {
}
-void
-ElectricalSystem::unbind ()
-{
+
+void FGElectricalSystem::unbind () {
}
-void
-ElectricalSystem::update (double dt)
-{
+
+void FGElectricalSystem::update (double dt) {
+ if ( !enabled ) {
+ return;
+ }
+
+ // cout << "Updating electrical system, dt = " << dt << endl;
+
+ unsigned int i;
+
+ // zero out the voltage before we start, but don't clear the
+ // requested load values.
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ suppliers[i]->set_volts( 0.0 );
+ }
+ for ( i = 0; i < buses.size(); ++i ) {
+ buses[i]->set_volts( 0.0 );
+ }
+ for ( i = 0; i < outputs.size(); ++i ) {
+ outputs[i]->set_volts( 0.0 );
+ }
+ for ( i = 0; i < connectors.size(); ++i ) {
+ connectors[i]->set_volts( 0.0 );
+ }
+
+ // for each "external" supplier, propagate the electrical current
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_EXTERNAL ) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ SG_LOG(SG_SYSTEMS, SG_ALERT,
+ "Error drawing more current than available!");
+ }
+ }
+ }
+
+ // for each "alternator" supplier, propagate the electrical
+ // current
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_ALTERNATOR) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ SG_LOG(SG_SYSTEMS, SG_ALERT,
+ "Error drawing more current than available!");
+ }
+ }
+ }
+
+ // for each "battery" supplier, propagate the electrical
+ // current
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_BATTERY ) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+ // cout << "battery load = " << load << endl;
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ SG_LOG(SG_SYSTEMS, SG_ALERT,
+ "Error drawing more current than available!");
+ }
+ }
+ }
+
+ float alt_norm
+ = fgGetFloat("/systems/electrical/suppliers/alternator") / 60.0;
+
+ // impliment an extremely simplistic voltage model (assumes
+ // certain naming conventions in electrical system config)
+ // FIXME: we probably want to be able to feed power from all
+ // engines if they are running and the master-alt is switched on
+ float volts = 0.0;
+ if ( fgGetBool("/controls/engines/engine[0]/master-bat") ) {
+ volts = 24.0;
+ }
+ if ( fgGetBool("/controls/engines/engine[0]/master-alt") ) {
+ if ( fgGetFloat("/engines/engine[0]/rpm") > 800 ) {
+ float alt_contrib = 28.0;
+ if ( alt_contrib > volts ) {
+ volts = alt_contrib;
+ }
+ } else if ( fgGetFloat("/engines/engine[0]/rpm") > 200 ) {
+ float alt_contrib = 20.0;
+ if ( alt_contrib > volts ) {
+ volts = alt_contrib;
+ }
+ }
+ }
+ _volts_out->setFloatValue( volts );
+
+ // impliment an extremely simplistic amps model (assumes certain
+ // naming conventions in the electrical system config) ... FIXME:
+ // make this more generic
+ float amps = 0.0;
+ if ( fgGetBool("/controls/engines/engine[0]/master-bat") ) {
+ if ( fgGetBool("/controls/engines/engine[0]/master-alt") &&
+ fgGetFloat("/engines/engine[0]/rpm") > 800 )
+ {
+ amps += 40.0 * alt_norm;
+ }
+ amps -= 15.0; // normal load
+ if ( fgGetBool("/controls/switches/flashing-beacon") ) {
+ amps -= 7.5;
+ }
+ if ( fgGetBool("/controls/switches/nav-lights") ) {
+ amps -= 7.5;
+ }
+ if ( amps > 7.0 ) {
+ amps = 7.0;
+ }
+ }
+ _amps_out->setFloatValue( amps );
+}
+
+
+bool FGElectricalSystem::build (SGPropertyNode* config_props) {
+ SGPropertyNode *node;
+ int i;
+
+ int count = config_props->nChildren();
+ for ( i = 0; i < count; ++i ) {
+ node = config_props->getChild(i);
+ string name = node->getName();
+ // cout << name << endl;
+ if ( name == "supplier" ) {
+ FGElectricalSupplier *s =
+ new FGElectricalSupplier( node );
+ suppliers.push_back( s );
+ } else if ( name == "bus" ) {
+ FGElectricalBus *b =
+ new FGElectricalBus( node );
+ buses.push_back( b );
+ } else if ( name == "output" ) {
+ FGElectricalOutput *o =
+ new FGElectricalOutput( node );
+ outputs.push_back( o );
+ } else if ( name == "connector" ) {
+ FGElectricalConnector *c =
+ new FGElectricalConnector( node, this );
+ connectors.push_back( c );
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "Unknown component type specified: "
+ << name );
+ return false;
+ }
+ }
+
+ return true;
+}
+
+
+// propagate the electrical current through the network, returns the
+// total current drawn by the children of this node.
+float FGElectricalSystem::propagate( FGElectricalComponent *node, double dt,
+ float input_volts, float input_amps,
+ string s ) {
+ s += " ";
+
+ float total_load = 0.0;
+
+ // determine the current to carry forward
+ float volts = 0.0;
+ if ( !fgGetBool("/systems/electrical/serviceable") ) {
+ volts = 0;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_SUPPLIER ) {
+ // cout << s << "is a supplier (" << node->get_name() << ")" << endl;
+ FGElectricalSupplier *supplier = (FGElectricalSupplier *)node;
+ if ( supplier->get_model() == FGElectricalSupplier::FG_BATTERY ) {
+ // cout << s << " (and is a battery)" << endl;
+ float battery_volts = supplier->get_output_volts();
+ if ( battery_volts < (input_volts - 0.1) ) {
+ // special handling of a battery charge condition
+ // cout << s << " (and is being charged) in v = "
+ // << input_volts << " current v = " << battery_volts
+ // << endl;
+ supplier->apply_load( -supplier->get_charge_amps(), dt );
+ return supplier->get_charge_amps();
+ }
+ }
+ volts = input_volts;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_BUS ) {
+ // cout << s << "is a bus (" << node->get_name() << ")" << endl;
+ volts = input_volts;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_OUTPUT ) {
+ // cout << s << "is an output (" << node->get_name() << ")" << endl;
+ volts = input_volts;
+ if ( volts > 1.0 ) {
+ // draw current if we have voltage
+ total_load = node->get_load_amps();
+ }
+ } else if ( node->get_kind() == FGElectricalComponent::FG_CONNECTOR ) {
+ // cout << s << "is a connector (" << node->get_name() << ")" << endl;
+ if ( ((FGElectricalConnector *)node)->get_state() ) {
+ volts = input_volts;
+ } else {
+ volts = 0.0;
+ }
+ // cout << s << " input_volts = " << volts << endl;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_ALERT, "unkown node type" );
+ }
+
+ int i;
+
+ // if this node has found a stronger power source, update the
+ // value and propagate to all children
+ if ( volts > node->get_volts() ) {
+ node->set_volts( volts );
+ for ( i = 0; i < node->get_num_outputs(); ++i ) {
+ FGElectricalComponent *child = node->get_output(i);
+ // send current equal to load
+ total_load += propagate( child, dt,
+ volts, child->get_load_amps(),
+ s );
+ }
+
+ // if not an output node, register the downstream current draw
+ // (sum of all children) with this node. If volts are zero,
+ // current draw should be zero.
+ if ( node->get_kind() != FGElectricalComponent::FG_OUTPUT ) {
+ node->set_load_amps( total_load );
+ }
+
+ node->set_available_amps( input_amps - total_load );
+
+ // publish values to specified properties
+ for ( i = 0; i < node->get_num_props(); ++i ) {
+ fgSetFloat( node->get_prop(i).c_str(), node->get_volts() );
+ }
+
+ /*
+ cout << s << node->get_name() << " -> (volts) " << node->get_volts()
+ << endl;
+ cout << s << node->get_name() << " -> (load amps) " << total_load
+ << endl;
+ cout << s << node->get_name() << " -> (input amps) " << input_amps
+ << endl;
+ cout << s << node->get_name() << " -> (extra amps) "
+ << node->get_available_amps() << endl;
+ */
+
+ return total_load;
+ } else {
+ // cout << s << "no further propagation" << endl;
+ return 0.0;
+ }
+}
+
+
+// search for the named component and return a pointer to it, NULL otherwise
+FGElectricalComponent *FGElectricalSystem::find ( const string &name ) {
+ unsigned int i;
+ string s;
+
+ // search suppliers
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ s = suppliers[i]->get_name();
+ // cout << " " << s << endl;
+ if ( s == name ) {
+ return suppliers[i];
+ }
+ }
+
+ // then search buses
+ for ( i = 0; i < buses.size(); ++i ) {
+ s = buses[i]->get_name();
+ // cout << " " << s << endl;
+ if ( s == name ) {
+ return buses[i];
+ }
+ }
+
+ // then search outputs
+ for ( i = 0; i < outputs.size(); ++i ) {
+ s = outputs[i]->get_name();
+ // cout << " " << s << endl;
+ if ( s == name ) {
+ return outputs[i];
+ }
+ }
+
+ // nothing found
+ return NULL;
}